diff --git a/lib/Doctrine/Migrations/MigrationRepository.php b/lib/Doctrine/Migrations/MigrationRepository.php
index 737ae4a537..85ddc3b9d5 100644
--- a/lib/Doctrine/Migrations/MigrationRepository.php
+++ b/lib/Doctrine/Migrations/MigrationRepository.php
@@ -19,14 +19,12 @@
 use function array_map;
 use function array_search;
 use function array_unshift;
-use function assert;
 use function class_exists;
 use function count;
 use function end;
 use function get_class;
 use function implode;
 use function is_array;
-use function is_int;
 use function ksort;
 use function sprintf;
 use function substr;
@@ -345,14 +343,18 @@ public function getRelativeVersion(string $version, int $delta) : ?string
 
         $offset = array_search($version, $versions, true);
 
-        assert($offset === false || is_int($offset));
+        if ($offset === false) {
+            return null;
+        }
+
+        $relativeVersion = ((int) $offset) + $delta;
 
-        if ($offset === false || ! isset($versions[$offset + $delta])) {
+        if (! isset($versions[$relativeVersion])) {
             // Unknown version or delta out of bounds.
             return null;
         }
 
-        return $versions[$offset + $delta];
+        return $versions[$relativeVersion];
     }
 
     public function getDeltaVersion(string $delta) : ?string
diff --git a/lib/Doctrine/Migrations/OutputWriter.php b/lib/Doctrine/Migrations/OutputWriter.php
index f0d9b29678..ebb04adfb0 100644
--- a/lib/Doctrine/Migrations/OutputWriter.php
+++ b/lib/Doctrine/Migrations/OutputWriter.php
@@ -12,10 +12,14 @@ class OutputWriter
     /** @var callable */
     private $callback;
 
+    /** @var string */
+    private $lastMessage = '';
+
     public function __construct(?callable $callback = null)
     {
         if ($callback === null) {
-            $callback = static function ($message) : void {
+            $callback = function (string $message) : void {
+                $this->lastMessage = $message;
             };
         }
 
@@ -31,4 +35,9 @@ public function write(string $message) : void
     {
         ($this->callback)($message);
     }
+
+    public function getLastMessage() : string
+    {
+        return $this->lastMessage;
+    }
 }
diff --git a/lib/Doctrine/Migrations/Tools/BytesFormatter.php b/lib/Doctrine/Migrations/Tools/BytesFormatter.php
index 2c6c3e9a30..91caabd057 100644
--- a/lib/Doctrine/Migrations/Tools/BytesFormatter.php
+++ b/lib/Doctrine/Migrations/Tools/BytesFormatter.php
@@ -22,6 +22,6 @@ public static function formatBytes(int $size, int $precision = 2) : string
         $base     = log($size, 1024);
         $suffixes = ['', 'K', 'M', 'G', 'T'];
 
-        return round(pow(1024, $base - floor($base)), $precision) . $suffixes[floor($base)];
+        return round(pow(1024, $base - floor($base)), $precision) . $suffixes[(int) floor($base)];
     }
 }
diff --git a/lib/Doctrine/Migrations/Tools/Console/Helper/MigrationDirectoryHelper.php b/lib/Doctrine/Migrations/Tools/Console/Helper/MigrationDirectoryHelper.php
index 00825fd143..d3a01ccf5c 100644
--- a/lib/Doctrine/Migrations/Tools/Console/Helper/MigrationDirectoryHelper.php
+++ b/lib/Doctrine/Migrations/Tools/Console/Helper/MigrationDirectoryHelper.php
@@ -71,9 +71,4 @@ private function createDirIfNotExists(string $dir) : void
 
         mkdir($dir, 0755, true);
     }
-
-    public function getName() : string
-    {
-        return 'MigrationDirectory';
-    }
 }
diff --git a/lib/Doctrine/Migrations/Version/Executor.php b/lib/Doctrine/Migrations/Version/Executor.php
index aafad0bd13..280bcbe926 100644
--- a/lib/Doctrine/Migrations/Version/Executor.php
+++ b/lib/Doctrine/Migrations/Version/Executor.php
@@ -26,7 +26,7 @@
  *
  * @internal
  */
-final class Executor implements ExecutorInterface
+class Executor implements ExecutorInterface
 {
     /** @var Configuration */
     private $configuration;
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 6a7ab1e9ee..1722859116 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -2,13 +2,23 @@ parameters:
     level: 7
     paths:
         - %currentWorkingDirectory%/lib
+        - %currentWorkingDirectory%/tests
+    autoload_directories:
+        - %currentWorkingDirectory%/tests/Doctrine/Migrations/Tests/Finder/_features
+        - %currentWorkingDirectory%/tests/Doctrine/Migrations/Tests/Finder/_files
+        - %currentWorkingDirectory%/tests/Doctrine/Migrations/Tests/Finder/_regression
+        - %currentWorkingDirectory%/tests/Doctrine/Migrations/Tests/Functional/_files
+    autoload_files:
+        - %currentWorkingDirectory%/tests/Doctrine/Migrations/Tests/Configuration/ConfigurationTestSource/Migrations/Version123.php
+        - %currentWorkingDirectory%/tests/Doctrine/Migrations/Tests/realpath.php
     ignoreErrors:
         # Ignore proxy manager magic
         - '~ProxyManager\\Proxy\\VirtualProxyInterface~'
-        - '~Parameter #1 \$files of method Doctrine\\Migrations\\Finder\\Finder::loadMigrationClasses\(\) expects array<string>, array<int, string\|false> given~'
-#'
+        - '~^Parameter #1 \$files of method Doctrine\\Migrations\\Finder\\Finder::loadMigrationClasses\(\) expects array<string>, array<int, string\|false> given\.\z~'
+        - '~^Class Doctrine\\Migrations\\Tests\\DoesNotExistAtAll not found\.\z~'
 
 includes:
     - vendor/phpstan/phpstan-deprecation-rules/rules.neon
     - vendor/phpstan/phpstan-phpunit/extension.neon
+    - vendor/phpstan/phpstan-phpunit/rules.neon
     - vendor/phpstan/phpstan-strict-rules/rules.neon
diff --git a/tests/Doctrine/Migrations/Tests/BoxPharCompileTest.php b/tests/Doctrine/Migrations/Tests/BoxPharCompileTest.php
index b4794ff309..d630dacd3d 100644
--- a/tests/Doctrine/Migrations/Tests/BoxPharCompileTest.php
+++ b/tests/Doctrine/Migrations/Tests/BoxPharCompileTest.php
@@ -6,6 +6,7 @@
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Process\Process;
+use function assert;
 use function file_exists;
 use function realpath;
 use function sprintf;
@@ -20,11 +21,13 @@ public function testCompile() : void
         $boxPharPath = __DIR__ . '/../../../../box.phar';
 
         if (! file_exists($boxPharPath)) {
-            $this->markTestSkipped('Download box with the ./download-box.sh shell script.');
+            self::markTestSkipped('Download box with the ./download-box.sh shell script.');
         }
 
         $boxPharPath = realpath($boxPharPath);
 
+        assert($boxPharPath !== false);
+
         $compilePharCommand = sprintf('php %s compile -vvv', $boxPharPath);
 
         $process = new Process($compilePharCommand);
@@ -32,6 +35,8 @@ public function testCompile() : void
 
         $doctrinePharPath = realpath(__DIR__ . '/../../../../build/doctrine-migrations.phar');
 
+        assert($doctrinePharPath !== false);
+
         self::assertTrue($process->isSuccessful());
         self::assertTrue(file_exists($doctrinePharPath));
 
diff --git a/tests/Doctrine/Migrations/Tests/Configuration/AbstractConfigurationTest.php b/tests/Doctrine/Migrations/Tests/Configuration/AbstractConfigurationTest.php
index 4ef51ce0ba..99811eb21e 100644
--- a/tests/Doctrine/Migrations/Tests/Configuration/AbstractConfigurationTest.php
+++ b/tests/Doctrine/Migrations/Tests/Configuration/AbstractConfigurationTest.php
@@ -156,8 +156,13 @@ public function testConfigurationFileNotExists() : void
 
     public function testLoadMigrationsList() : void
     {
-        self::assertInstanceOf(AbstractFileConfiguration::class, $this->loadConfiguration('migrations_list'));
-        self::assertInstanceOf(AbstractFileConfiguration::class, $this->loadConfiguration('migrations_list2'));
+        $configuration1 = $this->loadConfiguration('migrations_list');
+
+        self::assertContains('migrations_list', $configuration1->getFile());
+
+        $configuration2 = $this->loadConfiguration('migrations_list2');
+
+        self::assertContains('migrations_list2', $configuration2->getFile());
     }
 
     /**
@@ -165,10 +170,12 @@ public function testLoadMigrationsList() : void
      */
     public function testThatTheOrderOfConfigKeysDoesNotMatter(string $file) : void
     {
-        self::assertInstanceOf(AbstractFileConfiguration::class, $this->loadConfiguration($file));
+        $configuration = $this->loadConfiguration($file);
+
+        self::assertContains($file, $configuration->getFile());
     }
 
-    /** @return string[] */
+    /** @return string[][] */
     public function getConfigWithKeysInVariousOrder() : array
     {
         return [
diff --git a/tests/Doctrine/Migrations/Tests/Configuration/AbstractFileConfigurationTest.php b/tests/Doctrine/Migrations/Tests/Configuration/AbstractFileConfigurationTest.php
index 901926f4e7..c74e08c947 100644
--- a/tests/Doctrine/Migrations/Tests/Configuration/AbstractFileConfigurationTest.php
+++ b/tests/Doctrine/Migrations/Tests/Configuration/AbstractFileConfigurationTest.php
@@ -8,6 +8,7 @@
 use Doctrine\Migrations\Configuration\AbstractFileConfiguration;
 use Doctrine\Migrations\Configuration\Exception\InvalidConfigurationKey;
 use PHPUnit\Framework\TestCase;
+use function assert;
 use function basename;
 use function chdir;
 use function getcwd;
@@ -17,20 +18,22 @@ class AbstractFileConfigurationTest extends TestCase
     /** @var Connection */
     private $connection;
 
-    /** @var AbstractFileConfiguration */
+    /** @var TestAbstractFileConfiguration */
     private $fileConfiguration;
 
     public function testLoadChecksCurrentWorkingDirectory() : void
     {
         $cwd = getcwd();
 
+        assert($cwd !== false);
+
         chdir(__DIR__);
 
         $file = basename(__FILE__);
 
         $this->fileConfiguration->load($file);
 
-        $this->assertSame(__DIR__ . '/' . $file, $this->fileConfiguration->getFile());
+        self::assertSame(__DIR__ . '/' . $file, $this->fileConfiguration->getFile());
 
         chdir($cwd);
     }
@@ -52,50 +55,50 @@ public function testSetConfiguration() : void
             'setAllOrNothing',
         ]);
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setMigrationsNamespace')
             ->with('Doctrine');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setMigrationsTableName')
             ->with('migration_version');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setMigrationsColumnName')
             ->with('version_number');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setMigrationsColumnLength')
             ->with(200);
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setMigrationsExecutedAtColumnName')
             ->with('executed_at');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setMigrationsAreOrganizedByYearAndMonth');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setName')
             ->with('Migrations Test');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setMigrationsDirectory')
             ->with('migrations_directory');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('registerMigrationsFromDirectory')
             ->with('migrations_directory');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('registerMigration')
             ->with('001', 'Test');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setCustomTemplate')
             ->with('custom_template');
 
-        $fileConfiguration->expects($this->once())
+        $fileConfiguration->expects(self::once())
             ->method('setAllOrNothing')
             ->with(true);
 
diff --git a/tests/Doctrine/Migrations/Tests/Configuration/ConfigurationTest.php b/tests/Doctrine/Migrations/Tests/Configuration/ConfigurationTest.php
index 045ce926fb..8e38b67bd0 100644
--- a/tests/Doctrine/Migrations/Tests/Configuration/ConfigurationTest.php
+++ b/tests/Doctrine/Migrations/Tests/Configuration/ConfigurationTest.php
@@ -45,9 +45,17 @@ public function testConstructorSetsOutputWriter() : void
 
     public function testOutputWriterIsCreatedIfNotInjected() : void
     {
-        $configuration = new Configuration($this->getConnectionMock());
+        $dependencyFactory = $this->createMock(DependencyFactory::class);
+
+        $outputWriter = $this->getOutputWriterMock();
 
-        self::assertInstanceOf(OutputWriter::class, $configuration->getOutputWriter());
+        $dependencyFactory->expects(self::once())
+            ->method('getOutputWriter')
+            ->willReturn($outputWriter);
+
+        $configuration = new Configuration($this->getConnectionMock(), null, null, null, $dependencyFactory);
+
+        self::assertSame($outputWriter, $configuration->getOutputWriter());
     }
 
     public function testOutputWriterCanBeSet() : void
@@ -85,7 +93,10 @@ public function testVersionsTryToGetLoadedIfNotAlreadyLoadedWhenAccessingMethodT
         $configuration->setMigrationsNamespace(str_replace('\Version1Test', '', Version1Test::class));
         $configuration->setMigrationsDirectory(__DIR__ . '/../Stub/Configuration/AutoloadVersions');
 
-        $result = call_user_func_array([$configuration, $method], $args);
+        /** @var callable $callable */
+        $callable = [$configuration, $method];
+
+        $result = call_user_func_array($callable, $args);
 
         if ($method === 'getMigrationsToExecute') {
             $result = array_keys($result);
@@ -122,7 +133,10 @@ public function testVersionsTryToGetLoadedIfNotAlreadyLoadedWhenAccessingMethodT
         );
         $migrator->migrate('3Test');
 
-        $result = call_user_func_array([$configuration, $method], $args);
+        /** @var callable $callable */
+        $callable = [$configuration, $method];
+
+        $result = call_user_func_array($callable, $args);
 
         if ($method === 'getMigrationsToExecute') {
             $result = array_keys($result);
@@ -167,7 +181,7 @@ public function testMasterSlaveConnectionAlwaysConnectsToMaster() : void
     {
         $connection = $this->createMock(MasterSlaveConnection::class);
 
-        $connection->expects($this->once())
+        $connection->expects(self::once())
             ->method('connect')
             ->with('master')
             ->willReturn(true);
@@ -258,7 +272,7 @@ public function testGetQueryWriterCreatesAnInstanceIfItWasNotConfigured() : void
 
         $schemaManager = $this->createMock(AbstractSchemaManager::class);
 
-        $conn->expects($this->any())
+        $conn->expects(self::any())
             ->method('getSchemaManager')
             ->willReturn($schemaManager);
 
@@ -294,11 +308,11 @@ public function testGetVersionData() : void
             'executed_at' => '2018-05-16 11:14:40',
         ];
 
-        $dependencyFactory->expects($this->once())
+        $dependencyFactory->expects(self::once())
             ->method('getMigrationRepository')
             ->willReturn($migrationRepository);
 
-        $migrationRepository->expects($this->once())
+        $migrationRepository->expects(self::once())
             ->method('getVersionData')
             ->with($version)
             ->willReturn($versionData);
diff --git a/tests/Doctrine/Migrations/Tests/Configuration/Connection/Loader/ConnectionConfigurationLoaderTest.php b/tests/Doctrine/Migrations/Tests/Configuration/Connection/Loader/ConnectionConfigurationLoaderTest.php
index 56d3222a97..ea0cea4677 100644
--- a/tests/Doctrine/Migrations/Tests/Configuration/Connection/Loader/ConnectionConfigurationLoaderTest.php
+++ b/tests/Doctrine/Migrations/Tests/Configuration/Connection/Loader/ConnectionConfigurationLoaderTest.php
@@ -7,13 +7,17 @@
 use Doctrine\DBAL\Connection;
 use Doctrine\Migrations\Configuration\Configuration;
 use Doctrine\Migrations\Configuration\Connection\Loader\ConnectionConfigurationLoader;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 final class ConnectionConfigurationLoaderTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
+    /** @var ConnectionConfigurationLoader */
+    private $connectionConfigurationLoader;
+
     public function testChosenReturnsNull() : void
     {
         $connectionConfigurationLoader = new ConnectionConfigurationLoader();
@@ -25,7 +29,7 @@ public function testChosenReturnsConfigurationConnection() : void
     {
         $connection = $this->createMock(Connection::class);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getConnection')
             ->willReturn($connection);
 
diff --git a/tests/Doctrine/Migrations/Tests/ConfigurationTest.php b/tests/Doctrine/Migrations/Tests/ConfigurationTest.php
index cac57e3523..2bf43ace6b 100644
--- a/tests/Doctrine/Migrations/Tests/ConfigurationTest.php
+++ b/tests/Doctrine/Migrations/Tests/ConfigurationTest.php
@@ -12,7 +12,6 @@
 use Doctrine\Migrations\Tests\Stub\Version1Test;
 use Doctrine\Migrations\Tests\Stub\Version2Test;
 use Doctrine\Migrations\Tests\Stub\Version3Test;
-use Doctrine\Migrations\Version\Version;
 use function sys_get_temp_dir;
 
 class ConfigurationTest extends MigrationTestCase
@@ -131,7 +130,6 @@ public function testRegisterMigration() : void
         self::assertTrue($config->hasVersion('1234'));
 
         $version = $config->getVersion('1234');
-        self::assertInstanceOf(Version::class, $version);
         self::assertSame('1234', $version->getVersion());
         self::assertFalse($version->isMigrated());
     }
@@ -147,10 +145,10 @@ public function testRegisterMigrations() : void
         self::assertCount(2, $config->getMigrations(), 'Two Migration registered.');
 
         $version = $config->getVersion('1234');
-        self::assertInstanceOf(Version::class, $version);
+        self::assertSame('1234', $version->getVersion());
 
         $version = $config->getVersion('1235');
-        self::assertInstanceOf(Version::class, $version);
+        self::assertSame('1235', $version->getVersion());
     }
 
     public function testRegisterDuplicateVersion() : void
@@ -159,8 +157,8 @@ public function testRegisterDuplicateVersion() : void
 
         $config->registerMigration('1234', Version1Test::class);
 
-        $this->expectException(
-            MigrationException::class,
+        $this->expectException(MigrationException::class);
+        $this->expectExceptionMessage(
             'Migration version 1234 already registered with class Doctrine\Migrations\Version'
         );
         $config->registerMigration('1234', Version1Test::class);
@@ -348,7 +346,7 @@ public function testGetVersionAutoloadVersion(string $version) : void
 
         $result = $config->getVersion($version);
 
-        self::assertNotNull($result);
+        self::assertSame($version, $result->getVersion());
     }
 
     public function testGetVersionNotFound() : void
@@ -455,7 +453,7 @@ public function testSetCustomTemplateShould(?string $template) : void
     }
 
     /**
-     * @return string|null[][]
+     * @return string[][]|null[][]
      */
     public function validCustomTemplates() : array
     {
diff --git a/tests/Doctrine/Migrations/Tests/Event/Listeners/AutoCommitListenerTest.php b/tests/Doctrine/Migrations/Tests/Event/Listeners/AutoCommitListenerTest.php
index 7c5791736b..c03df1851c 100644
--- a/tests/Doctrine/Migrations/Tests/Event/Listeners/AutoCommitListenerTest.php
+++ b/tests/Doctrine/Migrations/Tests/Event/Listeners/AutoCommitListenerTest.php
@@ -9,10 +9,11 @@
 use Doctrine\Migrations\Event\Listeners\AutoCommitListener;
 use Doctrine\Migrations\Event\MigrationsEventArgs;
 use Doctrine\Migrations\Tests\MigrationTestCase;
+use PHPUnit\Framework\MockObject\MockObject;
 
 class AutoCommitListenerTest extends MigrationTestCase
 {
-    /** @var Connection */
+    /** @var Connection|MockObject */
     private $conn;
 
     /** @var AutoCommitListener */
@@ -28,7 +29,7 @@ public function testListenerDoesNothingDuringADryRun() : void
     public function testListenerDoesNothingWhenConnecitonAutoCommitIsOn() : void
     {
         $this->willNotCommit();
-        $this->conn->expects($this->once())
+        $this->conn->expects(self::once())
             ->method('isAutoCommit')
             ->willReturn(true);
 
@@ -37,10 +38,10 @@ public function testListenerDoesNothingWhenConnecitonAutoCommitIsOn() : void
 
     public function testListenerDoesFinalCommitWhenAutoCommitIsOff() : void
     {
-        $this->conn->expects($this->once())
+        $this->conn->expects(self::once())
             ->method('isAutoCommit')
             ->willReturn(false);
-        $this->conn->expects($this->once())
+        $this->conn->expects(self::once())
             ->method('commit');
 
         $this->listener->onMigrationsMigrated($this->createArgs(false));
diff --git a/tests/Doctrine/Migrations/Tests/FileQueryWriterTest.php b/tests/Doctrine/Migrations/Tests/FileQueryWriterTest.php
index f3d890f3ea..2d484828f9 100644
--- a/tests/Doctrine/Migrations/Tests/FileQueryWriterTest.php
+++ b/tests/Doctrine/Migrations/Tests/FileQueryWriterTest.php
@@ -46,7 +46,7 @@ public function testWrite(
             $migrationFileBuilder
         );
 
-        $platform->expects($this->any())
+        $platform->expects(self::any())
             ->method('getCurrentTimestampSQL')
             ->willReturn('CURRENT_TIMESTAMP');
 
@@ -85,14 +85,14 @@ public function testWrite(
         }
     }
 
-    /** @return string[][] */
+    /** @return mixed[][] */
     public function writeProvider() : array
     {
         $outputWriter = $this->createMock(OutputWriter::class);
 
-        $outputWriter->expects($this->atLeastOnce())
+        $outputWriter->expects(self::atLeastOnce())
             ->method('write')
-            ->with($this->isType('string'));
+            ->with(self::isType('string'));
 
         return [
             [__DIR__, Direction::UP, ['1' => ['SHOW DATABASES']], $outputWriter],
diff --git a/tests/Doctrine/Migrations/Tests/Finder/FinderTestCase.php b/tests/Doctrine/Migrations/Tests/Finder/FinderTestCase.php
index 55bbec6111..184f7ce2b4 100644
--- a/tests/Doctrine/Migrations/Tests/Finder/FinderTestCase.php
+++ b/tests/Doctrine/Migrations/Tests/Finder/FinderTestCase.php
@@ -16,7 +16,7 @@ public function testClassesInMultipleNamespacesCanBeLoadedByTheFinder() : void
     {
         $versions = $this->finder->findMigrations(__DIR__ . '/_features/MultiNamespace');
 
-        $this->assertSame([
+        self::assertSame([
             '0001' => 'TestMigrations\\Test\\Version0001',
             '0002' => 'TestMigrations\\TestOther\\Version0002',
         ], $versions);
@@ -29,6 +29,6 @@ public function testOnlyClassesInTheProvidedNamespaceAreLoadedWhenNamespaceIsPro
             'TestMigrations\\Test'
         );
 
-        $this->assertSame(['0001' => 'TestMigrations\\Test\\Version0001'], $versions);
+        self::assertSame(['0001' => 'TestMigrations\\Test\\Version0001'], $versions);
     }
 }
diff --git a/tests/Doctrine/Migrations/Tests/Finder/RecursiveRegexFinderTest.php b/tests/Doctrine/Migrations/Tests/Finder/RecursiveRegexFinderTest.php
index 8aed304a4d..2d60622f2c 100644
--- a/tests/Doctrine/Migrations/Tests/Finder/RecursiveRegexFinderTest.php
+++ b/tests/Doctrine/Migrations/Tests/Finder/RecursiveRegexFinderTest.php
@@ -56,7 +56,7 @@ public function testFindMigrationsReturnsTheExpectedFilesFromDirectory() : void
             self::assertArrayHasKey($version, $migrations);
             self::assertSame($namespace, $migrations[$version]);
         }
-        $migrationsForTestSort = (array) $migrations;
+        $migrationsForTestSort = $migrations;
 
         asort($migrationsForTestSort);
 
@@ -73,7 +73,7 @@ public function testFindMigrationsCanLocateClassesInNestedNamespacesAndDirectori
     {
         $versions = $this->finder->findMigrations(__DIR__ . '/_features/MultiNamespaceNested');
 
-        $this->assertSame([
+        self::assertSame([
             '0001' => 'TestMigrations\\MultiNested\\Version0001',
             '0002' => 'TestMigrations\\MultiNested\\Deep\\Version0002',
         ], $versions);
@@ -86,7 +86,7 @@ public function testMigrationsInSubnamespaceAreLoadedIfNamespaceIsParentNamespac
             'TestMigrations\\MultiNested'
         );
 
-        $this->assertSame([
+        self::assertSame([
             '0001' => 'TestMigrations\MultiNested\Version0001',
             '0002' => 'TestMigrations\MultiNested\Deep\Version0002',
         ], $versions);
@@ -99,7 +99,7 @@ public function testOnlyMigrationsInTheProvidedNamespacesAreLoadedIfNamespaceIsP
             'TestMigrations\\MultiNested\\Deep'
         );
 
-        $this->assertSame(['0002' => 'TestMigrations\MultiNested\Deep\Version0002'], $versions);
+        self::assertSame(['0002' => 'TestMigrations\MultiNested\Deep\Version0002'], $versions);
     }
 
     protected function setUp() : void
diff --git a/tests/Doctrine/Migrations/Tests/Functional/CliTest.php b/tests/Doctrine/Migrations/Tests/Functional/CliTest.php
index faf69700e5..856f3f1037 100644
--- a/tests/Doctrine/Migrations/Tests/Functional/CliTest.php
+++ b/tests/Doctrine/Migrations/Tests/Functional/CliTest.php
@@ -4,6 +4,7 @@
 
 namespace Doctrine\Migrations\Tests\Functional;
 
+use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\Schema\Schema;
 use Doctrine\DBAL\Tools\Console\Helper\ConnectionHelper;
 use Doctrine\Migrations\AbstractMigration;
@@ -23,6 +24,7 @@
 use Symfony\Component\Console\Input\ArrayInput;
 use const DIRECTORY_SEPARATOR;
 use function array_merge;
+use function assert;
 use function count;
 use function file_exists;
 use function file_get_contents;
@@ -299,7 +301,7 @@ protected function getSchema() : Schema
     }
 
     /**
-     * @return array|string[]
+     * @return string[]
      */
     private function findMigrations() : array
     {
@@ -325,7 +327,15 @@ private function getFileContentsForLatestVersion() : string
         $versionClassName      = reset($versions);
         $versionClassReflected = new ReflectionClass($versionClassName);
 
-        return file_get_contents($versionClassReflected->getFileName());
+        $fileName = $versionClassReflected->getFileName();
+
+        assert($fileName !== false);
+
+        $contents = file_get_contents($fileName);
+
+        assert($contents !== false);
+
+        return $contents;
     }
 }
 
diff --git a/tests/Doctrine/Migrations/Tests/Functional/FunctionalTest.php b/tests/Doctrine/Migrations/Tests/Functional/FunctionalTest.php
index 36518ad4bb..fa80ba8667 100644
--- a/tests/Doctrine/Migrations/Tests/Functional/FunctionalTest.php
+++ b/tests/Doctrine/Migrations/Tests/Functional/FunctionalTest.php
@@ -31,9 +31,11 @@
 use Doctrine\Migrations\Version\Version;
 use Symfony\Component\Process\Process;
 use Symfony\Component\Stopwatch\Stopwatch as SymfonyStopwatch;
+use function assert;
 use function file_exists;
 use function get_class_methods;
 use function in_array;
+use function is_array;
 use function sprintf;
 use function strtotime;
 use function unlink;
@@ -363,7 +365,7 @@ public function testSchemaChangeAreNotTakenIntoAccountInPreAndPostMethod() : voi
         $version = $this->createTestVersion($this->config, '1', MigrationModifySchemaInPreAndPost::class);
 
         self::assertFalse($this->config->hasVersionMigrated($version));
-        $queries = $version->execute('up');
+        $queries = $version->execute('up')->getSql();
 
         $schema = $this->connection->getSchemaManager()->createSchema();
         self::assertTrue($schema->hasTable('foo'), 'The table foo is not present');
@@ -375,7 +377,7 @@ public function testSchemaChangeAreNotTakenIntoAccountInPreAndPostMethod() : voi
             self::assertNotContains('bar2', $query);
         }
 
-        $queries = $version->execute('down');
+        $queries = $version->execute('down')->getSql();
 
         $schema = $this->connection->getSchemaManager()->createSchema();
         self::assertFalse($schema->hasTable('foo'), 'The table foo is present');
@@ -389,7 +391,7 @@ public function testSchemaChangeAreNotTakenIntoAccountInPreAndPostMethod() : voi
     }
 
     /**
-     * @return string[][]
+     * @return mixed[][]
      */
     public function provideTestMigrationNames() : array
     {
@@ -436,7 +438,7 @@ public function testMigrationWorksWhenNoCallsAreMadeToTheSchema() : void
                 continue;
             }
 
-            $schema->expects($this->never())->method($method);
+            $schema->expects(self::never())->method($method);
         }
     }
 
@@ -517,6 +519,8 @@ public function testMigrationExecutedAt() : void
         $row = $this->config->getConnection()
             ->fetchAssoc('SELECT * FROM test_migrations_table');
 
+        assert(is_array($row));
+
         self::assertSame('1', $row['current_version']);
         self::assertTrue(isset($row['executed_at']));
         self::assertNotNull($row['executed_at']);
@@ -524,7 +528,7 @@ public function testMigrationExecutedAt() : void
     }
 
     /**
-     * @return Connection|Configuration[]
+     * @return object[] [Connection, Configuration]
      */
     private static function fileConnectionAndConfig() : array
     {
diff --git a/tests/Doctrine/Migrations/Tests/Generator/DiffGeneratorTest.php b/tests/Doctrine/Migrations/Tests/Generator/DiffGeneratorTest.php
index 4782849166..54f1748e7f 100644
--- a/tests/Doctrine/Migrations/Tests/Generator/DiffGeneratorTest.php
+++ b/tests/Doctrine/Migrations/Tests/Generator/DiffGeneratorTest.php
@@ -13,26 +13,27 @@
 use Doctrine\Migrations\Generator\Generator;
 use Doctrine\Migrations\Generator\SqlGenerator;
 use Doctrine\Migrations\Provider\SchemaProviderInterface;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 class DiffGeneratorTest extends TestCase
 {
-    /** @var DBALConfiguration */
+    /** @var DBALConfiguration|MockObject */
     private $dbalConfiguration;
 
-    /** @var AbstractSchemaManager */
+    /** @var AbstractSchemaManager|MockObject */
     private $schemaManager;
 
-    /** @var SchemaProviderInterface */
+    /** @var SchemaProviderInterface|MockObject */
     private $schemaProvider;
 
-    /** @var AbstractPlatform */
+    /** @var AbstractPlatform|MockObject */
     private $platform;
 
-    /** @var Generator */
+    /** @var Generator|MockObject */
     private $migrationGenerator;
 
-    /** @var SqlGenerator */
+    /** @var SqlGenerator|MockObject */
     private $migrationSqlGenerator;
 
     /** @var DiffGenerator */
@@ -43,70 +44,70 @@ public function testGenerate() : void
         $fromSchema = $this->createMock(Schema::class);
         $toSchema   = $this->createMock(Schema::class);
 
-        $this->dbalConfiguration->expects($this->once())
+        $this->dbalConfiguration->expects(self::once())
             ->method('setFilterSchemaAssetsExpression')
             ->with('/table_name1/');
 
-        $this->dbalConfiguration->expects($this->once())
+        $this->dbalConfiguration->expects(self::once())
             ->method('getFilterSchemaAssetsExpression')
             ->willReturn('/table_name1/');
 
         $table1 = $this->createMock(Table::class);
-        $table1->expects($this->once())
+        $table1->expects(self::once())
             ->method('getName')
             ->willReturn('schema.table_name1');
 
         $table2 = $this->createMock(Table::class);
-        $table2->expects($this->once())
+        $table2->expects(self::once())
             ->method('getName')
             ->willReturn('schema.table_name2');
 
         $table3 = $this->createMock(Table::class);
-        $table3->expects($this->once())
+        $table3->expects(self::once())
             ->method('getName')
             ->willReturn('schema.table_name3');
 
-        $toSchema->expects($this->once())
+        $toSchema->expects(self::once())
             ->method('getTables')
             ->willReturn([$table1, $table2, $table3]);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('createSchema')
             ->willReturn($fromSchema);
 
-        $this->schemaProvider->expects($this->once())
+        $this->schemaProvider->expects(self::once())
             ->method('createSchema')
             ->willReturn($toSchema);
 
-        $toSchema->expects($this->at(1))
+        $toSchema->expects(self::at(1))
             ->method('dropTable')
             ->with('schema.table_name2');
 
-        $toSchema->expects($this->at(2))
+        $toSchema->expects(self::at(2))
             ->method('dropTable')
             ->with('schema.table_name3');
 
-        $fromSchema->expects($this->once())
+        $fromSchema->expects(self::once())
             ->method('getMigrateToSql')
             ->with($toSchema, $this->platform)
             ->willReturn(['UPDATE table SET value = 2']);
 
-        $fromSchema->expects($this->once())
+        $fromSchema->expects(self::once())
             ->method('getMigrateFromSql')
             ->with($toSchema, $this->platform)
             ->willReturn(['UPDATE table SET value = 1']);
 
-        $this->migrationSqlGenerator->expects($this->at(0))
+        $this->migrationSqlGenerator->expects(self::at(0))
             ->method('generate')
             ->with(['UPDATE table SET value = 2'], true, 80)
             ->willReturn('test1');
 
-        $this->migrationSqlGenerator->expects($this->at(1))
+        $this->migrationSqlGenerator->expects(self::at(1))
             ->method('generate')
             ->with(['UPDATE table SET value = 1'], true, 80)
             ->willReturn('test2');
 
-        $this->migrationGenerator->expects($this->once())
+        $this->migrationGenerator->expects(self::once())
             ->method('generateMigration')
             ->with('1234', 'test1', 'test2')
             ->willReturn('path');
@@ -122,16 +123,13 @@ protected function setUp() : void
         $this->platform               = $this->createMock(AbstractPlatform::class);
         $this->migrationGenerator     = $this->createMock(Generator::class);
         $this->migrationSqlGenerator  = $this->createMock(SqlGenerator::class);
-        $this->migrationDiffGenerator = $this->createMock(DiffGenerator::class);
-
         $this->migrationDiffGenerator = new DiffGenerator(
             $this->dbalConfiguration,
             $this->schemaManager,
             $this->schemaProvider,
             $this->platform,
             $this->migrationGenerator,
-            $this->migrationSqlGenerator,
-            $this->migrationDiffGenerator
+            $this->migrationSqlGenerator
         );
     }
 }
diff --git a/tests/Doctrine/Migrations/Tests/Generator/FileBuilderTest.php b/tests/Doctrine/Migrations/Tests/Generator/FileBuilderTest.php
index 071447f0f6..074733777b 100644
--- a/tests/Doctrine/Migrations/Tests/Generator/FileBuilderTest.php
+++ b/tests/Doctrine/Migrations/Tests/Generator/FileBuilderTest.php
@@ -8,11 +8,12 @@
 use Doctrine\DBAL\Platforms\AbstractPlatform;
 use Doctrine\Migrations\Generator\FileBuilder;
 use Doctrine\Migrations\Version\Direction;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 class FileBuilderTest extends TestCase
 {
-    /** @var AbstractPlatform */
+    /** @var AbstractPlatform|MockObject */
     private $platform;
 
     /** @var FileBuilder */
@@ -39,7 +40,7 @@ public function testBuildMigrationFile() : void
 
         $now = new DateTime('2018-09-01');
 
-        $this->platform->expects($this->any())
+        $this->platform->expects(self::any())
             ->method('getCurrentTimestampSQL')
             ->willReturn('CURRENT_TIMESTAMP');
 
diff --git a/tests/Doctrine/Migrations/Tests/Generator/GeneratorTest.php b/tests/Doctrine/Migrations/Tests/Generator/GeneratorTest.php
index c434615b13..b887efd0f8 100644
--- a/tests/Doctrine/Migrations/Tests/Generator/GeneratorTest.php
+++ b/tests/Doctrine/Migrations/Tests/Generator/GeneratorTest.php
@@ -7,6 +7,7 @@
 use Doctrine\Migrations\Configuration\Configuration;
 use Doctrine\Migrations\Generator\Generator;
 use InvalidArgumentException;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use function class_exists;
 use function file_get_contents;
@@ -17,7 +18,7 @@
 
 final class GeneratorTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
     /** @var Generator */
@@ -25,11 +26,11 @@ final class GeneratorTest extends TestCase
 
     public function testGenerateMigration() : void
     {
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getMigrationsNamespace')
             ->willReturn('Test');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getMigrationsDirectory')
             ->willReturn(sys_get_temp_dir());
 
@@ -55,7 +56,7 @@ public function testCustomTemplate() : void
 
         file_put_contents($customTemplate, 'custom template test');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getCustomTemplate')
             ->willReturn($customTemplate);
 
@@ -73,7 +74,7 @@ public function testCustomTemplateThrowsInvalidArgumentExceptionWhenTemplateMiss
         $this->expectException(InvalidArgumentException::class);
         $this->expectExceptionMessage('The specified template "invalid" cannot be found or is not readable.');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getCustomTemplate')
             ->willReturn('invalid');
 
@@ -92,13 +93,13 @@ public function testCustomTemplateThrowsInvalidArgumentExceptionWhenTemplateEmpt
             $customTemplate
         ));
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getCustomTemplate')
             ->willReturn($customTemplate);
 
         $this->migrationGenerator->generateMigration('1234');
 
-        unlink($path);
+        unlink($customTemplate);
     }
 
     protected function setUp() : void
diff --git a/tests/Doctrine/Migrations/Tests/Generator/SqlGeneratorTest.php b/tests/Doctrine/Migrations/Tests/Generator/SqlGeneratorTest.php
index 57a60f52fd..4dc9a5ba5e 100644
--- a/tests/Doctrine/Migrations/Tests/Generator/SqlGeneratorTest.php
+++ b/tests/Doctrine/Migrations/Tests/Generator/SqlGeneratorTest.php
@@ -7,16 +7,17 @@
 use Doctrine\DBAL\Platforms\AbstractPlatform;
 use Doctrine\Migrations\Configuration\Configuration;
 use Doctrine\Migrations\Generator\SqlGenerator;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use SqlFormatter;
 use function sprintf;
 
 final class SqlGeneratorTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var AbstractPlatform */
+    /** @var AbstractPlatform|MockObject */
     private $platform;
 
     /** @var SqlGenerator */
@@ -43,11 +44,11 @@ public function testGenerate() : void
 
         $expectedCode = sprintf($expectedCode, $formattedUpdate);
 
-        $this->configuration->expects($this->any())
+        $this->configuration->expects(self::any())
             ->method('getMigrationsTableName')
             ->willReturn('migrations_table_name');
 
-        $this->platform->expects($this->once())
+        $this->platform->expects(self::once())
             ->method('getName')
             ->willReturn('mysql');
 
diff --git a/tests/Doctrine/Migrations/Tests/Helper.php b/tests/Doctrine/Migrations/Tests/Helper.php
index 917a9a101e..fde13c7678 100644
--- a/tests/Doctrine/Migrations/Tests/Helper.php
+++ b/tests/Doctrine/Migrations/Tests/Helper.php
@@ -22,10 +22,25 @@ public static function deleteDir(string $path) : bool
         if ($path === '') {
             return false;
         }
-        $class_func = [self::class, __FUNCTION__];
 
-        return is_file($path) ?
-            @unlink($path) :
-            array_map($class_func, glob($path . '/*')) === @rmdir($path);
+        $classFunction = [self::class, __FUNCTION__];
+
+        if (is_file($path)) {
+            @unlink($path);
+
+            return true;
+        }
+
+        $files = glob($path . '/*');
+
+        if ($files !== []) {
+            array_map($classFunction, $files);
+
+            @rmdir($path);
+
+            return true;
+        }
+
+        return false;
     }
 }
diff --git a/tests/Doctrine/Migrations/Tests/MigrationPlanCalculatorTest.php b/tests/Doctrine/Migrations/Tests/MigrationPlanCalculatorTest.php
index 21dc0388bd..3a00221628 100644
--- a/tests/Doctrine/Migrations/Tests/MigrationPlanCalculatorTest.php
+++ b/tests/Doctrine/Migrations/Tests/MigrationPlanCalculatorTest.php
@@ -8,11 +8,12 @@
 use Doctrine\Migrations\MigrationRepository;
 use Doctrine\Migrations\Version\Direction;
 use Doctrine\Migrations\Version\Version;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 final class MigrationPlanCalculatorTest extends TestCase
 {
-    /** @var MigrationRepository */
+    /** @var MigrationRepository|MockObject */
     private $migrationRepository;
 
     /** @var MigrationPlanCalculator */
@@ -21,26 +22,26 @@ final class MigrationPlanCalculatorTest extends TestCase
     public function testGetMigrationsToExecuteUp() : void
     {
         $version1 = $this->createMock(Version::class);
-        $version1->expects($this->any())
+        $version1->expects(self::any())
             ->method('getVersion')
             ->willReturn('01');
 
         $version2 = $this->createMock(Version::class);
-        $version2->expects($this->any())
+        $version2->expects(self::any())
             ->method('getVersion')
             ->willReturn('02');
 
         $version3 = $this->createMock(Version::class);
-        $version3->expects($this->any())
+        $version3->expects(self::any())
             ->method('getVersion')
             ->willReturn('03');
 
         $version4 = $this->createMock(Version::class);
-        $version4->expects($this->any())
+        $version4->expects(self::any())
             ->method('getVersion')
             ->willReturn('04');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getMigrations')
             ->willReturn([
                 '01' => $version1,
@@ -49,7 +50,7 @@ public function testGetMigrationsToExecuteUp() : void
                 '04' => $version4,
             ]);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getMigratedVersions')
             ->willReturn([
                 '02',
@@ -72,26 +73,26 @@ public function testGetMigrationsToExecuteUp() : void
     public function testGetMigrationsToExecuteDown() : void
     {
         $version1 = $this->createMock(Version::class);
-        $version1->expects($this->any())
+        $version1->expects(self::any())
             ->method('getVersion')
             ->willReturn('01');
 
         $version2 = $this->createMock(Version::class);
-        $version2->expects($this->any())
+        $version2->expects(self::any())
             ->method('getVersion')
             ->willReturn('02');
 
         $version3 = $this->createMock(Version::class);
-        $version3->expects($this->any())
+        $version3->expects(self::any())
             ->method('getVersion')
             ->willReturn('03');
 
         $version4 = $this->createMock(Version::class);
-        $version4->expects($this->any())
+        $version4->expects(self::any())
             ->method('getVersion')
             ->willReturn('04');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getMigrations')
             ->willReturn([
                 '01' => $version1,
@@ -100,7 +101,7 @@ public function testGetMigrationsToExecuteDown() : void
                 '04' => $version4,
             ]);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getMigratedVersions')
             ->willReturn([
                 '02',
diff --git a/tests/Doctrine/Migrations/Tests/MigrationRepositoryTest.php b/tests/Doctrine/Migrations/Tests/MigrationRepositoryTest.php
index 40956d7b17..2cb5fd6db9 100644
--- a/tests/Doctrine/Migrations/Tests/MigrationRepositoryTest.php
+++ b/tests/Doctrine/Migrations/Tests/MigrationRepositoryTest.php
@@ -11,20 +11,21 @@
 use Doctrine\Migrations\MigrationRepository;
 use Doctrine\Migrations\Version\Factory;
 use Doctrine\Migrations\Version\Version;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 class MigrationRepositoryTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var Connection */
+    /** @var Connection|MockObject */
     private $connection;
 
-    /** @var MigrationFinder */
+    /** @var MigrationFinder|MockObject */
     private $migrationFinder;
 
-    /** @var Factory */
+    /** @var Factory|MockObject */
     private $versionFactory;
 
     /** @var MigrationRepository */
@@ -39,12 +40,12 @@ public function testGetDeltaVersionReturnsNull() : void
     public function testGetVersions() : void
     {
         $version1 = $this->createMock(Version::class);
-        $version1->expects($this->once())
+        $version1->expects(self::once())
             ->method('getVersion')
             ->willReturn('01');
 
         $version2 = $this->createMock(Version::class);
-        $version2->expects($this->once())
+        $version2->expects(self::once())
             ->method('getVersion')
             ->willReturn('02');
 
@@ -66,21 +67,21 @@ public function testGetVersionData() : void
     {
         $version = $this->createMock(Version::class);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('connect');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('createMigrationTable');
 
-        $this->configuration->expects($this->exactly(2))
+        $this->configuration->expects(self::exactly(2))
             ->method('getQuotedMigrationsColumnName')
             ->willReturn('version');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getQuotedMigrationsExecutedAtColumnName')
             ->willReturn('executed_at');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getMigrationsTableName')
             ->willReturn('versions');
 
@@ -89,7 +90,7 @@ public function testGetVersionData() : void
             'executed_at' => '2018-05-16 11:14:40',
         ];
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('fetchAssoc')
             ->with('SELECT version, executed_at FROM versions WHERE version = ?')
             ->willReturn($versionData);
diff --git a/tests/Doctrine/Migrations/Tests/MigrationTestCase.php b/tests/Doctrine/Migrations/Tests/MigrationTestCase.php
index 758219f873..5b442233d2 100644
--- a/tests/Doctrine/Migrations/Tests/MigrationTestCase.php
+++ b/tests/Doctrine/Migrations/Tests/MigrationTestCase.php
@@ -12,14 +12,15 @@
 use Doctrine\Migrations\Stopwatch;
 use Exception;
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\Console\Output\Output;
 use Symfony\Component\Console\Output\StreamOutput;
 use Symfony\Component\Stopwatch\Stopwatch as SymfonyStopwatch;
+use function assert;
 use function fopen;
 use function fwrite;
 use function glob;
 use function is_dir;
 use function is_file;
+use function is_resource;
 use function mkdir;
 use function realpath;
 use function rewind;
@@ -30,7 +31,7 @@ abstract class MigrationTestCase extends TestCase
     /** @var OutputWriter */
     private $outputWriter;
 
-    /** @var  Output */
+    /** @var  StreamOutput */
     protected $output;
 
     public function getSqliteConnection() : Connection
@@ -53,6 +54,8 @@ public function getOutputStream() : StreamOutput
     {
         $stream = fopen('php://memory', 'r+', false);
 
+        assert(is_resource($stream));
+
         return new StreamOutput($stream);
     }
 
@@ -68,6 +71,9 @@ public function getOutputStreamContent(StreamOutput $streamOutput) : string
     public function getInputStream(string $input)
     {
         $stream = fopen('php://memory', 'r+', false);
+
+        assert(is_resource($stream));
+
         fwrite($stream, $input);
         rewind($stream);
 
@@ -76,7 +82,7 @@ public function getInputStream(string $input)
 
     protected function getOutputWriter() : OutputWriter
     {
-        if (! $this->outputWriter) {
+        if ($this->outputWriter === null) {
             $this->output       = $this->getOutputStream();
             $output             = $this->output;
             $this->outputWriter = new OutputWriter(static function ($message) use ($output) {
diff --git a/tests/Doctrine/Migrations/Tests/MigratorTest.php b/tests/Doctrine/Migrations/Tests/MigratorTest.php
index c84c3cd995..838896e20b 100644
--- a/tests/Doctrine/Migrations/Tests/MigratorTest.php
+++ b/tests/Doctrine/Migrations/Tests/MigratorTest.php
@@ -4,7 +4,7 @@
 
 namespace Doctrine\Migrations\Tests;
 
-use Doctrine\DBAL\Driver\Connection;
+use Doctrine\DBAL\Connection;
 use Doctrine\Migrations\Configuration\Configuration;
 use Doctrine\Migrations\DependencyFactory;
 use Doctrine\Migrations\Exception\MigrationException;
@@ -18,7 +18,7 @@
 use Doctrine\Migrations\Tests\Stub\Functional\MigrationThrowsError;
 use Doctrine\Migrations\Version\Direction;
 use PHPUnit\Framework\Constraint\RegularExpression;
-use PHPUnit_Framework_MockObject_MockObject;
+use PHPUnit\Framework\MockObject\MockObject;
 use Symfony\Component\Console\Output\StreamOutput;
 use Throwable;
 use const DIRECTORY_SEPARATOR;
@@ -64,24 +64,24 @@ public function testWriteSqlDown() : void
             ->setMethods(['getSql'])
             ->getMock();
 
-        $migration->expects($this->once())
+        $migration->expects(self::once())
             ->method('getSql')
             ->with('1')
             ->willReturn($sql);
 
-        $migrationRepository->expects($this->once())
+        $migrationRepository->expects(self::once())
             ->method('getCurrentVersion')
             ->willReturn('5');
 
-        $outputWriter->expects($this->once())
+        $outputWriter->expects(self::once())
             ->method('write')
             ->with("-- Migrating from 5 to 1\n");
 
-        $configuration->expects($this->once())
+        $configuration->expects(self::once())
             ->method('getQueryWriter')
             ->willReturn($queryWriter);
 
-        $queryWriter->expects($this->once())
+        $queryWriter->expects(self::once())
             ->method('write')
             ->with('/path', Direction::DOWN, $sql);
 
@@ -134,15 +134,15 @@ public function testMigrateWithNoMigrationsDontThrowsExceptionIfContiniousIntegr
      */
     public function testGetSql(?string $to) : void
     {
-        /** @var Migration|PHPUnit_Framework_MockObject_MockObject $migration */
+        /** @var Migrator|MockObject $migration */
         $migration = $this->getMockBuilder(Migrator::class)
             ->disableOriginalConstructor()
             ->setMethods(['migrate'])
             ->getMock();
 
-        $expected = ['something'];
+        $expected = [['something']];
 
-        $migration->expects($this->once())
+        $migration->expects(self::once())
             ->method('migrate')
             ->with($to)
             ->willReturn($expected);
@@ -152,7 +152,7 @@ public function testGetSql(?string $to) : void
         self::assertSame($expected, $result);
     }
 
-    /** @return string|null[] */
+    /** @return mixed[][] */
     public function getSqlProvider() : array
     {
         return [
@@ -175,7 +175,7 @@ public function testWriteSqlFile(string $path, string $from, ?string $to, array
             ->with($path, new RegularExpression('/(up|down)/'), $getSqlReturn)
             ->willReturn(true);
 
-        $outputWriter->expects($this->atLeastOnce())
+        $outputWriter->expects(self::atLeastOnce())
             ->method('write');
 
         /** @var Configuration|PHPUnit_Framework_MockObject_MockObject $migration */
@@ -184,15 +184,15 @@ public function testWriteSqlFile(string $path, string $from, ?string $to, array
         $dependencyFactory   = $this->createMock(DependencyFactory::class);
         $migrationRepository = $this->createMock(MigrationRepository::class);
 
-        $config->expects($this->once())
+        $config->expects(self::once())
             ->method('getDependencyFactory')
             ->willReturn($dependencyFactory);
 
-        $dependencyFactory->expects($this->once())
+        $dependencyFactory->expects(self::once())
             ->method('getMigrationRepository')
             ->willReturn($migrationRepository);
 
-        $dependencyFactory->expects($this->once())
+        $dependencyFactory->expects(self::once())
             ->method('getOutputWriter')
             ->willReturn($outputWriter);
 
@@ -207,16 +207,16 @@ public function testWriteSqlFile(string $path, string $from, ?string $to, array
 
         if ($to === null) { // this will always just test the "up" direction
             $config->method('getLatestVersion')
-                ->willReturn($from + 1);
+                ->willReturn((int) $from + 1);
         }
 
-        /** @var Migration|PHPUnit_Framework_MockObject_MockObject $migration */
+        /** @var Migrator|MockObject $migration */
         $migration = $this->getMockBuilder(Migrator::class)
             ->setConstructorArgs($this->getMigratorConstructorArgs($config))
             ->setMethods(['getSql'])
             ->getMock();
 
-        $migration->expects($this->once())
+        $migration->expects(self::once())
             ->method('getSql')
             ->with($to)
             ->willReturn($getSqlReturn);
@@ -225,7 +225,7 @@ public function testWriteSqlFile(string $path, string $from, ?string $to, array
     }
 
     /**
-     * @return string[][]
+     * @return mixed[][]
      */
     public function writeSqlFileProvider() : array
     {
diff --git a/tests/Doctrine/Migrations/Tests/OutputWriterTest.php b/tests/Doctrine/Migrations/Tests/OutputWriterTest.php
index c5d12eb1b3..253e7e8843 100644
--- a/tests/Doctrine/Migrations/Tests/OutputWriterTest.php
+++ b/tests/Doctrine/Migrations/Tests/OutputWriterTest.php
@@ -19,7 +19,9 @@ public function testDefaultCallback() : void
     {
         $outputWriter = new OutputWriter();
 
-        self::assertNull($outputWriter->write('test message'));
+        $outputWriter->write('test message');
+
+        self::assertSame('test message', $outputWriter->getLastMessage());
     }
 
     public function testWrite() : void
diff --git a/tests/Doctrine/Migrations/Tests/ParameterFormatterTest.php b/tests/Doctrine/Migrations/Tests/ParameterFormatterTest.php
index 4a66e46b81..377b4a9fa9 100644
--- a/tests/Doctrine/Migrations/Tests/ParameterFormatterTest.php
+++ b/tests/Doctrine/Migrations/Tests/ParameterFormatterTest.php
@@ -64,7 +64,7 @@ protected function setUp() : void
 
         $this->platform = $this->createMock(AbstractPlatform::class);
 
-        $this->connection->expects($this->any())
+        $this->connection->expects(self::any())
             ->method('getDatabasePlatform')
             ->willReturn($this->platform);
 
diff --git a/tests/Doctrine/Migrations/Tests/Provider/OrmSchemaProviderTest.php b/tests/Doctrine/Migrations/Tests/Provider/OrmSchemaProviderTest.php
index bb2bf6bd7d..b437edfd16 100644
--- a/tests/Doctrine/Migrations/Tests/Provider/OrmSchemaProviderTest.php
+++ b/tests/Doctrine/Migrations/Tests/Provider/OrmSchemaProviderTest.php
@@ -5,7 +5,6 @@
 namespace Doctrine\Migrations\Tests\Provider;
 
 use Doctrine\DBAL\Connection;
-use Doctrine\DBAL\Schema\Schema;
 use Doctrine\Migrations\Provider\OrmSchemaProvider;
 use Doctrine\Migrations\Tests\MigrationTestCase;
 use Doctrine\ORM\Configuration;
@@ -35,7 +34,6 @@ class OrmSchemaProviderTest extends MigrationTestCase
     public function testCreateSchemaFetchesMetadataFromEntityManager() : void
     {
         $schema = $this->ormProvider->createSchema();
-        self::assertInstanceOf(Schema::class, $schema);
         self::assertTrue($schema->hasTable('sample_entity'));
         $table = $schema->getTable('sample_entity');
         self::assertTrue($table->hasColumn('id'));
diff --git a/tests/Doctrine/Migrations/Tests/RollupTest.php b/tests/Doctrine/Migrations/Tests/RollupTest.php
index ac3dd31d55..d55d84c351 100644
--- a/tests/Doctrine/Migrations/Tests/RollupTest.php
+++ b/tests/Doctrine/Migrations/Tests/RollupTest.php
@@ -9,18 +9,19 @@
 use Doctrine\Migrations\MigrationRepository;
 use Doctrine\Migrations\Rollup;
 use Doctrine\Migrations\Version\Version;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use RuntimeException;
 
 class RollupTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var Connection */
+    /** @var Connection|MockObject */
     private $connection;
 
-    /** @var MigrationRepository */
+    /** @var MigrationRepository|MockObject */
     private $migrationRepository;
 
     /** @var Rollup */
@@ -31,7 +32,7 @@ public function testRollupNoMigrtionsFoundException() : void
         $this->expectException(RuntimeException::class);
         $this->expectExceptionMessage('No migrations found.');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getVersions')
             ->willReturn([]);
 
@@ -51,7 +52,7 @@ public function testRollupTooManyMigrationsException() : void
             '02' => $version2,
         ];
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getVersions')
             ->willReturn($versions);
 
@@ -64,22 +65,22 @@ public function testRollup() : void
 
         $versions = ['01' => $version1];
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getVersions')
             ->willReturn($versions);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getMigrationsTableName')
             ->willReturn('versions');
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('executeQuery')
             ->with('DELETE FROM versions');
 
-        $version1->expects($this->once())
+        $version1->expects(self::once())
             ->method('markMigrated');
 
-        $this->assertSame($version1, $this->rollup->rollup());
+        self::assertSame($version1, $this->rollup->rollup());
     }
 
     protected function setUp() : void
diff --git a/tests/Doctrine/Migrations/Tests/SchemaDumperTest.php b/tests/Doctrine/Migrations/Tests/SchemaDumperTest.php
index 7e44d5221b..1781daaa85 100644
--- a/tests/Doctrine/Migrations/Tests/SchemaDumperTest.php
+++ b/tests/Doctrine/Migrations/Tests/SchemaDumperTest.php
@@ -11,21 +11,22 @@
 use Doctrine\Migrations\Generator\Generator;
 use Doctrine\Migrations\Generator\SqlGenerator;
 use Doctrine\Migrations\SchemaDumper;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use RuntimeException;
 
 class SchemaDumperTest extends TestCase
 {
-    /** @var AbstractPlatform */
+    /** @var AbstractPlatform|MockObject */
     private $platform;
 
-    /** @var AbstractSchemaManager */
+    /** @var AbstractSchemaManager|MockObject */
     private $schemaManager;
 
-    /** @var Generator */
+    /** @var Generator|MockObject */
     private $migrationGenerator;
 
-    /** @var SqlGenerator */
+    /** @var SqlGenerator|MockObject */
     private $migrationSqlGenerator;
 
     /** @var SchemaDumper */
@@ -38,11 +39,11 @@ public function testDumpNoTablesException() : void
 
         $schema = $this->createMock(Schema::class);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('createSchema')
             ->willReturn($schema);
 
-        $schema->expects($this->once())
+        $schema->expects(self::once())
             ->method('getTables')
             ->willReturn([]);
 
@@ -55,33 +56,33 @@ public function testDump() : void
 
         $schema = $this->createMock(Schema::class);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('createSchema')
             ->willReturn($schema);
 
-        $schema->expects($this->once())
+        $schema->expects(self::once())
             ->method('getTables')
             ->willReturn([$table]);
 
-        $this->platform->expects($this->once())
+        $this->platform->expects(self::once())
             ->method('getCreateTableSQL')
             ->willReturn(['CREATE TABLE test']);
 
-        $this->platform->expects($this->once())
+        $this->platform->expects(self::once())
             ->method('getDropTableSQL')
             ->willReturn('DROP TABLE test');
 
-        $this->migrationSqlGenerator->expects($this->at(0))
+        $this->migrationSqlGenerator->expects(self::at(0))
             ->method('generate')
             ->with(['CREATE TABLE test'])
             ->willReturn('up');
 
-        $this->migrationSqlGenerator->expects($this->at(1))
+        $this->migrationSqlGenerator->expects(self::at(1))
             ->method('generate')
             ->with(['DROP TABLE test'])
             ->willReturn('down');
 
-        $this->migrationGenerator->expects($this->once())
+        $this->migrationGenerator->expects(self::once())
             ->method('generateMigration')
             ->with('1234', 'up', 'down')
             ->willReturn('/path/to/migration.php');
diff --git a/tests/Doctrine/Migrations/Tests/StopwatchTest.php b/tests/Doctrine/Migrations/Tests/StopwatchTest.php
index a79e50949b..022a29236b 100644
--- a/tests/Doctrine/Migrations/Tests/StopwatchTest.php
+++ b/tests/Doctrine/Migrations/Tests/StopwatchTest.php
@@ -7,7 +7,6 @@
 use Doctrine\Migrations\Stopwatch;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Stopwatch\Stopwatch as SymfonyStopwatch;
-use Symfony\Component\Stopwatch\StopwatchEvent;
 
 class StopwatchTest extends TestCase
 {
@@ -18,12 +17,9 @@ public function testStart() : void
     {
         $stopwatchEvent = $this->stopwatch->start('test');
 
-        self::assertInstanceOf(StopwatchEvent::class, $stopwatchEvent);
         self::assertSame('default', $stopwatchEvent->getCategory());
 
         $stopwatchEvent->stop();
-
-        self::assertNotNull($stopwatchEvent->getDuration());
     }
 
     protected function setUp() : void
diff --git a/tests/Doctrine/Migrations/Tests/Stub/AbstractMigrationStub.php b/tests/Doctrine/Migrations/Tests/Stub/AbstractMigrationStub.php
index ef9e9dcf21..6061903cf1 100644
--- a/tests/Doctrine/Migrations/Tests/Stub/AbstractMigrationStub.php
+++ b/tests/Doctrine/Migrations/Tests/Stub/AbstractMigrationStub.php
@@ -18,7 +18,7 @@ public function down(Schema $schema) : void
     {
     }
 
-    public function exposedWrite(?string $message = null) : void
+    public function exposedWrite(string $message) : void
     {
         $this->write($message);
     }
diff --git a/tests/Doctrine/Migrations/Tests/Stub/EventVerificationListener.php b/tests/Doctrine/Migrations/Tests/Stub/EventVerificationListener.php
index c363878d2a..c390e7b69c 100644
--- a/tests/Doctrine/Migrations/Tests/Stub/EventVerificationListener.php
+++ b/tests/Doctrine/Migrations/Tests/Stub/EventVerificationListener.php
@@ -10,7 +10,7 @@
 
 final class EventVerificationListener implements EventSubscriber
 {
-    /** @var EventArgs[] */
+    /** @var EventArgs[][] */
     public $events = [];
 
     /** @return string[] */
diff --git a/tests/Doctrine/Migrations/Tests/Stub/VersionDryRunTypes.php b/tests/Doctrine/Migrations/Tests/Stub/VersionDryRunTypes.php
index 66b86cff60..3e7307a668 100644
--- a/tests/Doctrine/Migrations/Tests/Stub/VersionDryRunTypes.php
+++ b/tests/Doctrine/Migrations/Tests/Stub/VersionDryRunTypes.php
@@ -9,15 +9,15 @@
 
 class VersionDryRunTypes extends AbstractMigration
 {
-    /** @var int[] */
+    /** @var mixed[] */
     private $value;
 
     /** @var int[] */
     private $type;
 
     /**
-     * @param int[] $value
-     * @param int[] $type
+     * @param mixed[] $value
+     * @param int[]   $type
      */
     public function setParam(array $value, array $type) : void
     {
diff --git a/tests/Doctrine/Migrations/Tests/Stub/VersionOutputSqlWithParam.php b/tests/Doctrine/Migrations/Tests/Stub/VersionOutputSqlWithParam.php
index 7dff0469ab..1852f679ef 100644
--- a/tests/Doctrine/Migrations/Tests/Stub/VersionOutputSqlWithParam.php
+++ b/tests/Doctrine/Migrations/Tests/Stub/VersionOutputSqlWithParam.php
@@ -9,14 +9,14 @@
 
 class VersionOutputSqlWithParam extends AbstractMigration
 {
-    /** @var int[] */
+    /** @var mixed[] */
     private $param = [
         'param1' => 1,
         'param2' => 2,
         'param3' => 3,
     ];
 
-    /** @param int[] $param */
+    /** @param mixed[] $param */
     public function setParam(array $param) : void
     {
         $this->param = $param;
diff --git a/tests/Doctrine/Migrations/Tests/Stub/VersionOutputSqlWithParamAndType.php b/tests/Doctrine/Migrations/Tests/Stub/VersionOutputSqlWithParamAndType.php
index a1fa918e7c..e758272276 100644
--- a/tests/Doctrine/Migrations/Tests/Stub/VersionOutputSqlWithParamAndType.php
+++ b/tests/Doctrine/Migrations/Tests/Stub/VersionOutputSqlWithParamAndType.php
@@ -10,13 +10,13 @@
 
 class VersionOutputSqlWithParamAndType extends AbstractMigration
 {
-    /** @var int[] */
+    /** @var mixed[] */
     private $param = ['param1' => 1];
 
     /** @var int[] */
     private $type = [Connection::PARAM_STR_ARRAY];
 
-    /** @param int[] $param */
+    /** @param mixed[] $param */
     public function setParam(array $param) : void
     {
         $this->param = $param;
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/AbstractCommandTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/AbstractCommandTest.php
index e917377eb8..054c9e94f7 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/AbstractCommandTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/AbstractCommandTest.php
@@ -19,6 +19,7 @@
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\Output;
 use Symfony\Component\Console\Output\OutputInterface;
+use function assert;
 use function chdir;
 use function getcwd;
 
@@ -46,7 +47,7 @@ public function invokeMigrationConfigurationGetter(
             ['command']
         );
 
-        if ($helperSet !== null && $helperSet instanceof HelperSet) {
+        if ($helperSet instanceof HelperSet) {
             $command->setHelperSet($helperSet);
         } else {
             $command->setHelperSet(new HelperSet());
@@ -77,7 +78,7 @@ public function testSetConnection() : void
 
         $command->setConnection($connection);
 
-        $this->assertSame($connection, $command->getConnection());
+        self::assertSame($connection, $command->getConnection());
     }
 
     public function testGetMigrationConfigurationDefaultsToConnection() : void
@@ -89,7 +90,7 @@ public function testGetMigrationConfigurationDefaultsToConnection() : void
         $command = new TestAbstractCommand();
         $command->setMigrationConfiguration($configuration);
 
-        $this->assertSame($configuration, $command->getConfiguration($input, $output));
+        self::assertSame($configuration, $command->getConfiguration($input, $output));
     }
 
     /**
@@ -103,8 +104,8 @@ public function testInjectedMigrationConfigurationIsBeingReturned() : void
             ->getMock();
 
         $input->method('getOption')
-            ->with($this->logicalOr($this->equalTo('db-configuration'), $this->equalTo('configuration')))
-            ->will($this->returnValue(null));
+            ->with(self::logicalOr(self::equalTo('db-configuration'), self::equalTo('configuration')))
+            ->will(self::returnValue(null));
 
         $configuration = $this->createMock(Configuration::class);
 
@@ -122,12 +123,11 @@ public function testMigrationConfigurationReturnsConnectionFromHelperSet() : voi
             ->getMock();
 
         $input->method('getOption')
-            ->with($this->logicalOr($this->equalTo('db-configuration'), $this->equalTo('configuration')))
-            ->will($this->returnValue(null));
+            ->with(self::logicalOr(self::equalTo('db-configuration'), self::equalTo('configuration')))
+            ->will(self::returnValue(null));
 
         $actualConfiguration = $this->invokeMigrationConfigurationGetter($input);
 
-        self::assertInstanceOf(Configuration::class, $actualConfiguration);
         self::assertSame('pdo_sqlite', $actualConfiguration->getConnection()->getDriver()->getName());
     }
 
@@ -142,13 +142,12 @@ public function testMigrationConfigurationReturnsConnectionFromInputOption() : v
             ->getMock();
 
         $input->method('getOption')
-            ->will($this->returnValueMap([
+            ->will(self::returnValueMap([
                 ['db-configuration', __DIR__ . '/_files/db-config.php'],
             ]));
 
         $actualConfiguration = $this->invokeMigrationConfigurationGetter($input);
 
-        self::assertInstanceOf(Configuration::class, $actualConfiguration);
         self::assertSame('pdo_sqlite', $actualConfiguration->getConnection()->getDriver()->getName());
     }
 
@@ -163,7 +162,7 @@ public function testMigrationConfigurationReturnsConfigurationFileOption() : voi
             ->getMock();
 
         $input->method('getOption')
-            ->will($this->returnValueMap([
+            ->will(self::returnValueMap([
                 ['configuration', __DIR__ . '/_files/config.yml'],
             ]));
 
@@ -188,7 +187,6 @@ public function testMigrationConfigurationReturnsConnectionFromConfigurationIfNo
         $configuration       = new Configuration($connection);
         $actualConfiguration = $this->invokeMigrationConfigurationGetter($input, $configuration, true);
 
-        self::assertInstanceOf(Configuration::class, $actualConfiguration);
         self::assertSame($connection, $actualConfiguration->getConnection());
         self::assertSame('doctrine_migration_versions', $actualConfiguration->getMigrationsTableName());
         self::assertNull($actualConfiguration->getMigrationsNamespace());
@@ -217,7 +215,7 @@ public function testMigrationsConfigurationFromCommandLineOverridesInjectedConfi
             ->getMock();
 
         $input->method('getOption')
-            ->will($this->returnValueMap([
+            ->will(self::returnValueMap([
                 ['configuration', __DIR__ . '/_files/config.yml'],
             ]));
 
@@ -247,7 +245,7 @@ public function testInjectedConfigurationIsPreferedOverConfigFileIsCurrentWorkin
             ->getMock();
 
         $input->method('getOption')
-            ->will($this->returnValueMap([
+            ->will(self::returnValueMap([
                 ['configuration', null],
             ]));
 
@@ -300,11 +298,7 @@ private function invokeAbstractCommandConfirmation(
 
         $input->setStream($this->getInputStream($response . "\n"));
 
-        if ($helper instanceof QuestionHelper) {
-            $helperSet = new HelperSet(['question' => $helper]);
-        } else {
-            $helperSet = new HelperSet(['dialog' => $helper]);
-        }
+        $helperSet = new HelperSet(['question' => $helper]);
 
         $command->setHelperSet($helperSet);
 
@@ -326,7 +320,11 @@ public function testAskConfirmation() : void
 
     protected function setUp() : void
     {
-        $this->originalCwd = getcwd();
+        $cwd = getcwd();
+
+        assert($cwd !== false);
+
+        $this->originalCwd = $cwd;
     }
 
     protected function tearDown() : void
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/CommandTestCase.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/CommandTestCase.php
index 613eccb0cf..7fb0e355d9 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/CommandTestCase.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/CommandTestCase.php
@@ -54,7 +54,7 @@ protected function createCommandTester() : CommandTester
      * @param mixed[] $args
      * @param mixed[] $options
      *
-     * @return CommandTester|int[]
+     * @return mixed[] [CommandTester, int]
      */
     protected function executeCommand(array $args, array $options = []) : array
     {
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DialogSupport.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DialogSupport.php
index aee92f62ef..3c38e0b739 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DialogSupport.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DialogSupport.php
@@ -22,7 +22,7 @@ protected function configureDialogs(Application $app) : void
 
     protected function willAskConfirmationAndReturn(bool $bool) : void
     {
-        $this->questions->expects($this->once())
+        $this->questions->expects(self::once())
             ->method('ask')
             ->willReturn($bool);
     }
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DiffCommandTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DiffCommandTest.php
index b988107010..3e9b43a95b 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DiffCommandTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DiffCommandTest.php
@@ -7,19 +7,20 @@
 use Doctrine\Migrations\Configuration\Configuration;
 use Doctrine\Migrations\Generator\DiffGenerator;
 use Doctrine\Migrations\Tools\Console\Command\DiffCommand;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 
 final class DiffCommandTest extends TestCase
 {
-    /** @var DiffGenerator */
+    /** @var DiffGenerator|MockObject */
     private $migrationDiffGenerator;
 
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var DiffCommand */
+    /** @var DiffCommand|MockObject */
     private $diffCommand;
 
     public function testExecute() : void
@@ -27,44 +28,44 @@ public function testExecute() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('generateVersionNumber')
             ->willReturn('1234');
 
-        $input->expects($this->at(0))
+        $input->expects(self::at(0))
             ->method('getOption')
             ->with('filter-expression')
             ->willReturn('filter expression');
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('formatted')
             ->willReturn(true);
 
-        $input->expects($this->at(2))
+        $input->expects(self::at(2))
             ->method('getOption')
             ->with('line-length')
             ->willReturn(80);
 
-        $input->expects($this->at(3))
+        $input->expects(self::at(3))
             ->method('getOption')
             ->with('editor-cmd')
             ->willReturn('mate');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('generateVersionNumber')
             ->willReturn('1234');
 
-        $this->migrationDiffGenerator->expects($this->once())
+        $this->migrationDiffGenerator->expects(self::once())
             ->method('generate')
             ->with('1234', 'filter expression', true, 80)
             ->willReturn('/path/to/migration.php');
 
-        $this->diffCommand->expects($this->once())
+        $this->diffCommand->expects(self::once())
             ->method('procOpen')
             ->with('mate', '/path/to/migration.php');
 
-        $output->expects($this->once())
+        $output->expects(self::once())
             ->method('writeln')
             ->with([
                 'Generated new migration class to "<info>/path/to/migration.php</info>"',
@@ -88,7 +89,7 @@ protected function setUp() : void
 
         $this->diffCommand->setMigrationConfiguration($this->configuration);
 
-        $this->diffCommand->expects($this->once())
+        $this->diffCommand->expects(self::once())
             ->method('createMigrationDiffGenerator')
             ->willReturn($this->migrationDiffGenerator);
     }
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DumpSchemaCommandTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DumpSchemaCommandTest.php
index ebcc32f4b0..96e2f8e827 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DumpSchemaCommandTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/DumpSchemaCommandTest.php
@@ -10,6 +10,7 @@
 use Doctrine\Migrations\SchemaDumper;
 use Doctrine\Migrations\Tools\Console\Command\DumpSchemaCommand;
 use Doctrine\Migrations\Version\Version;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use RuntimeException;
 use Symfony\Component\Console\Input\InputInterface;
@@ -17,19 +18,19 @@
 
 final class DumpSchemaCommandTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var DependencyFactory */
+    /** @var DependencyFactory|MockObject */
     private $dependencyFactory;
 
-    /** @var MigrationRepository */
+    /** @var MigrationRepository|MockObject */
     private $migrationRepository;
 
-    /** @var SchemaDumper */
+    /** @var SchemaDumper|MockObject */
     private $schemaDumper;
 
-    /** @var GenerateCommand */
+    /** @var DumpSchemaCommand|MockObject */
     private $dumpSchemaCommand;
 
     public function testExecuteThrowsRuntimeException() : void
@@ -44,7 +45,7 @@ public function testExecuteThrowsRuntimeException() : void
 
         $versions = [$version];
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getVersions')
             ->willReturn($versions);
 
@@ -56,36 +57,36 @@ public function testExecute() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $input->expects($this->at(0))
+        $input->expects(self::at(0))
             ->method('getOption')
             ->with('formatted')
             ->willReturn(true);
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('line-length')
             ->willReturn(80);
 
-        $input->expects($this->at(2))
+        $input->expects(self::at(2))
             ->method('getOption')
             ->with('editor-cmd')
             ->willReturn('test');
 
         $versions = [];
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getVersions')
             ->willReturn($versions);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('generateVersionNumber')
             ->willReturn('1234');
 
-        $this->schemaDumper->expects($this->once())
+        $this->schemaDumper->expects(self::once())
             ->method('dump')
             ->with('1234', true, 80);
 
-        $output->expects($this->once())
+        $output->expects(self::once())
             ->method('writeln')
             ->with([
                 'Dumped your schema to a new migration class at "<info></info>"',
@@ -107,7 +108,7 @@ protected function setUp() : void
         $this->migrationRepository = $this->createMock(MigrationRepository::class);
         $this->schemaDumper        = $this->createMock(SchemaDumper::class);
 
-        $this->dependencyFactory->expects($this->any())
+        $this->dependencyFactory->expects(self::any())
             ->method('getSchemaDumper')
             ->willReturn($this->schemaDumper);
 
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/ExecuteCommandTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/ExecuteCommandTest.php
index 2f9ab164e8..cfefee5e1e 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/ExecuteCommandTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/ExecuteCommandTest.php
@@ -7,6 +7,7 @@
 use Doctrine\Migrations\MigrationRepository;
 use Doctrine\Migrations\Tools\Console\Command\ExecuteCommand;
 use Doctrine\Migrations\Version\Version;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -14,10 +15,10 @@
 
 class ExecuteCommandTest extends TestCase
 {
-    /** @var MigrationRepository */
+    /** @var MigrationRepository|MockObject */
     private $migrationRepository;
 
-    /** @var ExecuteCommand */
+    /** @var ExecuteCommand|MockObject */
     private $executeCommand;
 
     public function testWriteSqlCustomPath() : void
@@ -28,27 +29,27 @@ public function testWriteSqlCustomPath() : void
         $output  = $this->createMock(OutputInterface::class);
         $version = $this->createMock(Version::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn($versionName);
 
-        $input->expects($this->at(3))
+        $input->expects(self::at(3))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn('/path');
 
-        $input->expects($this->at(4))
+        $input->expects(self::at(4))
             ->method('getOption')
             ->with('down')
             ->willReturn(true);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getVersion')
             ->with($versionName)
             ->willReturn($version);
 
-        $version->expects($this->once())
+        $version->expects(self::once())
             ->method('writeSqlFile')
             ->with('/path', 'down');
 
@@ -63,27 +64,27 @@ public function testWriteSqlCurrentWorkingDirectory() : void
         $output  = $this->createMock(OutputInterface::class);
         $version = $this->createMock(Version::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn($versionName);
 
-        $input->expects($this->at(3))
+        $input->expects(self::at(3))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn(null);
 
-        $input->expects($this->at(4))
+        $input->expects(self::at(4))
             ->method('getOption')
             ->with('down')
             ->willReturn(true);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getVersion')
             ->with($versionName)
             ->willReturn($version);
 
-        $version->expects($this->once())
+        $version->expects(self::once())
             ->method('writeSqlFile')
             ->with(getcwd(), 'down');
 
@@ -98,37 +99,37 @@ public function testExecute() : void
         $output  = $this->createMock(OutputInterface::class);
         $version = $this->createMock(Version::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn($versionName);
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('query-time')
             ->willReturn(true);
 
-        $input->expects($this->at(2))
+        $input->expects(self::at(2))
             ->method('getOption')
             ->with('dry-run')
             ->willReturn(true);
 
-        $input->expects($this->at(3))
+        $input->expects(self::at(3))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn(false);
 
-        $input->expects($this->at(4))
+        $input->expects(self::at(4))
             ->method('getOption')
             ->with('down')
             ->willReturn(true);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getVersion')
             ->with($versionName)
             ->willReturn($version);
 
-        $version->expects($this->once())
+        $version->expects(self::once())
             ->method('execute')
             ->with('down');
 
@@ -143,41 +144,41 @@ public function testExecuteCancel() : void
         $output  = $this->createMock(OutputInterface::class);
         $version = $this->createMock(Version::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn($versionName);
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('query-time')
             ->willReturn(true);
 
-        $input->expects($this->at(2))
+        $input->expects(self::at(2))
             ->method('getOption')
             ->with('dry-run')
             ->willReturn(false);
 
-        $input->expects($this->at(3))
+        $input->expects(self::at(3))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn(false);
 
-        $input->expects($this->at(4))
+        $input->expects(self::at(4))
             ->method('getOption')
             ->with('down')
             ->willReturn(true);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getVersion')
             ->with($versionName)
             ->willReturn($version);
 
-        $this->executeCommand->expects($this->once())
+        $this->executeCommand->expects(self::once())
             ->method('canExecute')
             ->willReturn(false);
 
-        $version->expects($this->never())
+        $version->expects(self::never())
             ->method('execute');
 
         self::assertSame(1, $this->executeCommand->execute($input, $output));
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/GenerateCommandTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/GenerateCommandTest.php
index b3555a2ad9..a73a08d340 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/GenerateCommandTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/GenerateCommandTest.php
@@ -8,22 +8,23 @@
 use Doctrine\Migrations\DependencyFactory;
 use Doctrine\Migrations\Generator\Generator;
 use Doctrine\Migrations\Tools\Console\Command\GenerateCommand;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 
 final class GenerateCommandTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var DependencyFactory */
+    /** @var DependencyFactory|MockObject */
     private $dependencyFactory;
 
-    /** @var Generator */
+    /** @var Generator|MockObject */
     private $migrationGenerator;
 
-    /** @var GenerateCommand */
+    /** @var GenerateCommand|MockObject */
     private $generateCommand;
 
     public function testExecute() : void
@@ -31,25 +32,25 @@ public function testExecute() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getOption')
             ->with('editor-cmd')
             ->willReturn('mate');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('generateVersionNumber')
             ->willReturn('1234');
 
-        $this->migrationGenerator->expects($this->once())
+        $this->migrationGenerator->expects(self::once())
             ->method('generateMigration')
             ->with('1234')
             ->willReturn('/path/to/migration.php');
 
-        $this->generateCommand->expects($this->once())
+        $this->generateCommand->expects(self::once())
             ->method('procOpen')
             ->with('mate', '/path/to/migration.php');
 
-        $output->expects($this->once())
+        $output->expects(self::once())
             ->method('writeln')
             ->with([
                 'Generated new migration class to "<info>/path/to/migration.php</info>"',
@@ -68,7 +69,7 @@ protected function setUp() : void
         $this->dependencyFactory  = $this->createMock(DependencyFactory::class);
         $this->migrationGenerator = $this->createMock(Generator::class);
 
-        $this->dependencyFactory->expects($this->once())
+        $this->dependencyFactory->expects(self::once())
             ->method('getMigrationGenerator')
             ->willReturn($this->migrationGenerator);
 
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrateCommandTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrateCommandTest.php
index ffdb600150..daf9e93056 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrateCommandTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrateCommandTest.php
@@ -9,6 +9,7 @@
 use Doctrine\Migrations\MigrationRepository;
 use Doctrine\Migrations\Migrator;
 use Doctrine\Migrations\Tools\Console\Command\MigrateCommand;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -16,13 +17,16 @@
 
 class MigrateCommandTest extends TestCase
 {
-    /** @var DependencyFactory */
+    /** @var DependencyFactory|MockObject */
     private $dependencyFactory;
 
-    /** @var MigrationRepository */
+    /** @var MigrationRepository|MockObject */
     private $migrationRepository;
 
-    /** @var MigrateCommand */
+    /** @var Configuration|MockObject */
+    private $configuration;
+
+    /** @var MigrateCommand|MockObject */
     private $migrateCommand;
 
     public function testExecuteCouldNotResolveAlias() : void
@@ -30,16 +34,16 @@ public function testExecuteCouldNotResolveAlias() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('1234');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('1234')
             ->willReturn('');
@@ -52,21 +56,21 @@ public function testExecuteAlreadyAtFirstVersion() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('prev');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('prev')
             ->willReturn(null);
 
-        $output->expects($this->at(4))
+        $output->expects(self::at(4))
             ->method('writeln')
             ->with('<error>Already at first version.</error>');
 
@@ -78,21 +82,21 @@ public function testExecuteAlreadyAtLatestVersion() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('next');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('next')
             ->willReturn(null);
 
-        $output->expects($this->at(4))
+        $output->expects(self::at(4))
             ->method('writeln')
             ->with('<error>Already at latest version.</error>');
 
@@ -104,21 +108,21 @@ public function testExecuteTheDeltaCouldNotBeReached() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('current-1');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('current-1')
             ->willReturn(null);
 
-        $output->expects($this->at(4))
+        $output->expects(self::at(4))
             ->method('writeln')
             ->with('<error>The delta couldn\'t be reached.</error>');
 
@@ -130,21 +134,21 @@ public function testExecuteUnknownVersion() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('unknown');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('unknown')
             ->willReturn(null);
 
-        $output->expects($this->at(4))
+        $output->expects(self::at(4))
             ->method('writeln')
             ->with('<error>Unknown version: unknown</error>');
 
@@ -156,25 +160,25 @@ public function testExecutedUnavailableMigrationsCancel() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('prev');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('prev')
             ->willReturn('1234');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getExecutedUnavailableMigrations')
             ->willReturn(['1235']);
 
-        $this->migrateCommand->expects($this->once())
+        $this->migrateCommand->expects(self::once())
             ->method('canExecute')
             ->willReturn(false);
 
@@ -188,38 +192,38 @@ public function testExecuteWriteSqlCustomPath() : void
 
         $migration = $this->createMock(Migrator::class);
 
-        $this->dependencyFactory->expects($this->once())
+        $this->dependencyFactory->expects(self::once())
             ->method('getMigrator')
             ->willReturn($migration);
 
-        $migration->expects($this->once())
+        $migration->expects(self::once())
             ->method('writeSqlFile')
             ->with('test', '1234');
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('prev');
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn('test');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('prev')
             ->willReturn('1234');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getExecutedUnavailableMigrations')
             ->willReturn(['1235']);
 
-        $this->migrateCommand->expects($this->once())
+        $this->migrateCommand->expects(self::once())
             ->method('canExecute')
             ->willReturn(true);
 
@@ -233,38 +237,38 @@ public function testExecuteWriteSqlCurrentWorkingDirectory() : void
 
         $migrator = $this->createMock(Migrator::class);
 
-        $this->dependencyFactory->expects($this->once())
+        $this->dependencyFactory->expects(self::once())
             ->method('getMigrator')
             ->willReturn($migrator);
 
-        $migrator->expects($this->once())
+        $migrator->expects(self::once())
             ->method('writeSqlFile')
             ->with(getcwd(), '1234');
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('prev');
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn(null);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('prev')
             ->willReturn('1234');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getExecutedUnavailableMigrations')
             ->willReturn(['1235']);
 
-        $this->migrateCommand->expects($this->once())
+        $this->migrateCommand->expects(self::once())
             ->method('canExecute')
             ->willReturn(true);
 
@@ -278,44 +282,44 @@ public function testExecuteMigrate() : void
 
         $migrator = $this->createMock(Migrator::class);
 
-        $this->dependencyFactory->expects($this->once())
+        $this->dependencyFactory->expects(self::once())
             ->method('getMigrator')
             ->willReturn($migrator);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('prev');
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('prev')
             ->willReturn('1234');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getExecutedUnavailableMigrations')
             ->willReturn(['1235']);
 
-        $this->migrateCommand->expects($this->at(0))
+        $this->migrateCommand->expects(self::at(0))
             ->method('canExecute')
             ->with('Are you sure you wish to continue? (y/n)')
             ->willReturn(true);
 
-        $this->migrateCommand->expects($this->at(1))
+        $this->migrateCommand->expects(self::at(1))
             ->method('canExecute')
             ->with('WARNING! You are about to execute a database migration that could result in schema changes and data loss. Are you sure you wish to continue? (y/n)')
             ->willReturn(true);
 
-        $migrator->expects($this->once())
+        $migrator->expects(self::once())
             ->method('migrate')
             ->with('1234');
 
@@ -329,64 +333,64 @@ public function testExecuteMigrateAllOrNothing() : void
 
         $migrator = $this->createMock(Migrator::class);
 
-        $this->dependencyFactory->expects($this->once())
+        $this->dependencyFactory->expects(self::once())
             ->method('getMigrator')
             ->willReturn($migrator);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('prev');
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn(false);
 
-        $input->expects($this->at(2))
+        $input->expects(self::at(2))
             ->method('getOption')
             ->with('allow-no-migration')
             ->willReturn(false);
 
-        $input->expects($this->at(3))
+        $input->expects(self::at(3))
             ->method('getOption')
             ->with('query-time')
             ->willReturn(false);
 
-        $input->expects($this->at(4))
+        $input->expects(self::at(4))
             ->method('getOption')
             ->with('dry-run')
             ->willReturn(false);
 
-        $input->expects($this->at(5))
+        $input->expects(self::at(5))
             ->method('getOption')
             ->with('all-or-nothing')
             ->willReturn(true);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('prev')
             ->willReturn('1234');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getExecutedUnavailableMigrations')
             ->willReturn(['1235']);
 
-        $this->migrateCommand->expects($this->at(0))
+        $this->migrateCommand->expects(self::at(0))
             ->method('canExecute')
             ->with('Are you sure you wish to continue? (y/n)')
             ->willReturn(true);
 
-        $this->migrateCommand->expects($this->at(1))
+        $this->migrateCommand->expects(self::at(1))
             ->method('canExecute')
             ->with('WARNING! You are about to execute a database migration that could result in schema changes and data loss. Are you sure you wish to continue? (y/n)')
             ->willReturn(true);
 
-        $migrator->expects($this->once())
+        $migrator->expects(self::once())
             ->method('migrate')
             ->with('1234');
 
@@ -400,39 +404,39 @@ public function testExecuteMigrateCancelExecutedUnavailableMigrations() : void
 
         $migrator = $this->createMock(Migrator::class);
 
-        $this->dependencyFactory->expects($this->never())
+        $this->dependencyFactory->expects(self::never())
             ->method('getMigrator')
             ->willReturn($migrator);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('prev');
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('prev')
             ->willReturn('1234');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getExecutedUnavailableMigrations')
             ->willReturn(['1235']);
 
-        $this->migrateCommand->expects($this->once())
+        $this->migrateCommand->expects(self::once())
             ->method('canExecute')
             ->with('Are you sure you wish to continue? (y/n)')
             ->willReturn(false);
 
-        $migrator->expects($this->never())
+        $migrator->expects(self::never())
             ->method('migrate');
 
         self::assertSame(1, $this->migrateCommand->execute($input, $output));
@@ -445,44 +449,44 @@ public function testExecuteMigrateCancel() : void
 
         $migrator = $this->createMock(Migrator::class);
 
-        $this->dependencyFactory->expects($this->once())
+        $this->dependencyFactory->expects(self::once())
             ->method('getMigrator')
             ->willReturn($migrator);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getArgument')
             ->with('version')
             ->willReturn('prev');
 
-        $input->expects($this->at(1))
+        $input->expects(self::at(1))
             ->method('getOption')
             ->with('write-sql')
             ->willReturn(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('setIsDryRun')
             ->with(false);
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('resolveVersionAlias')
             ->with('prev')
             ->willReturn('1234');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getExecutedUnavailableMigrations')
             ->willReturn(['1235']);
 
-        $this->migrateCommand->expects($this->at(0))
+        $this->migrateCommand->expects(self::at(0))
             ->method('canExecute')
             ->with('Are you sure you wish to continue? (y/n)')
             ->willReturn(true);
 
-        $this->migrateCommand->expects($this->at(1))
+        $this->migrateCommand->expects(self::at(1))
             ->method('canExecute')
             ->with('WARNING! You are about to execute a database migration that could result in schema changes and data loss. Are you sure you wish to continue? (y/n)')
             ->willReturn(false);
 
-        $migrator->expects($this->never())
+        $migrator->expects(self::never())
             ->method('migrate');
 
         self::assertSame(1, $this->migrateCommand->execute($input, $output));
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrationStatusTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrationStatusTest.php
index be25472d89..f284f04058 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrationStatusTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrationStatusTest.php
@@ -16,9 +16,8 @@ class MigrationStatusTest extends MigrationTestCase
     /** @var string */
     private $migrationDirectory;
 
-    public function __construct()
+    protected function setUp() : void
     {
-        parent::__construct(null, [], null);
         $this->migrationDirectory = __DIR__ . '/../../../Stub/migration-empty-folder';
     }
 
@@ -64,27 +63,27 @@ protected function assertVersion(string $alias, ?string $version, string $label,
             ->getMock();
 
         $configuration
-            ->expects($this->exactly(4))
+            ->expects(self::exactly(4))
             ->method('resolveVersionAlias')
-            ->will($this->returnCallback(static function ($argAlias) use ($alias, $version) {
+            ->will(self::returnCallback(static function ($argAlias) use ($alias, $version) {
                 return $argAlias === $alias ? $version : '999';
             }));
 
         $configuration
             ->method('getDateTime')
-            ->will($this->returnValue('FORMATTED'));
+            ->will(self::returnValue('FORMATTED'));
 
         $configuration
             ->method('getAvailableVersions')
-            ->will($this->returnValue([]));
+            ->will(self::returnValue([]));
 
         $configuration->setMigrationsNamespace('DoctrineMigrations');
         $configuration->setMigrationsDirectory($this->migrationDirectory);
 
         $command
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('getMigrationConfiguration')
-            ->will($this->returnValue($configuration));
+            ->will(self::returnValue($configuration));
 
         $commandTester = new CommandTester($command);
         $commandTester->execute(
@@ -121,9 +120,9 @@ public function testShowVersions() : void
             ->getMock();
 
         $command
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('getMigrationConfiguration')
-            ->will($this->returnValue($configuration));
+            ->will(self::returnValue($configuration));
 
         $commandTester = new CommandTester($command);
         $commandTester->execute(
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrationVersionTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrationVersionTest.php
index 254a4319b4..1038480a0e 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrationVersionTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/MigrationVersionTest.php
@@ -9,12 +9,13 @@
 use Doctrine\Migrations\Tests\Stub\Version1Test;
 use Doctrine\Migrations\Tools\Console\Command\VersionCommand;
 use InvalidArgumentException;
+use PHPUnit\Framework\MockObject\MockObject;
 use Symfony\Component\Console\Tester\CommandTester;
 use function sys_get_temp_dir;
 
 class MigrationVersionTest extends MigrationTestCase
 {
-    /** @var VersionCommand */
+    /** @var VersionCommand|MockObject */
     private $command;
 
     /** @var Configuration */
@@ -33,9 +34,9 @@ protected function setUp() : void
         $this->configuration->setMigrationsDirectory(sys_get_temp_dir());
 
         $this->command
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('getMigrationConfiguration')
-            ->will($this->returnValue($this->configuration));
+            ->will(self::returnValue($this->configuration));
     }
 
     /**
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/RollupCommandTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/RollupCommandTest.php
index c1840ff126..f448453ba2 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/RollupCommandTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/RollupCommandTest.php
@@ -8,19 +8,20 @@
 use Doctrine\Migrations\Rollup;
 use Doctrine\Migrations\Tools\Console\Command\RollupCommand;
 use Doctrine\Migrations\Version\Version;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 
 final class RollupCommandTest extends TestCase
 {
-    /** @var DependencyFactory */
+    /** @var DependencyFactory|MockObject */
     private $dependencyFactory;
 
-    /** @var Rollup */
+    /** @var Rollup|MockObject */
     private $rollup;
 
-    /** @var RollupCommand */
+    /** @var RollupCommand|MockObject */
     private $rollupCommand;
 
     public function testExecute() : void
@@ -29,15 +30,15 @@ public function testExecute() : void
         $output = $this->createMock(OutputInterface::class);
 
         $version = $this->createMock(Version::class);
-        $version->expects($this->once())
+        $version->expects(self::once())
             ->method('getVersion')
             ->willReturn('1234');
 
-        $this->rollup->expects($this->once())
+        $this->rollup->expects(self::once())
             ->method('rollup')
             ->willReturn($version);
 
-        $output->expects($this->once())
+        $output->expects(self::once())
             ->method('writeln')
             ->with('Rolled up migrations to version <info>1234</info>');
 
@@ -49,7 +50,7 @@ protected function setUp() : void
         $this->rollup            = $this->createMock(Rollup::class);
         $this->dependencyFactory = $this->createMock(DependencyFactory::class);
 
-        $this->dependencyFactory->expects($this->any())
+        $this->dependencyFactory->expects(self::any())
             ->method('getRollup')
             ->willReturn($this->rollup);
 
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/StatusCommandTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/StatusCommandTest.php
index 9baff4d341..7ffeaa3dc7 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/StatusCommandTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/StatusCommandTest.php
@@ -12,22 +12,23 @@
 use Doctrine\Migrations\Tools\Console\Command\StatusCommand;
 use Doctrine\Migrations\Tools\Console\Helper\MigrationStatusInfosHelper;
 use Doctrine\Migrations\Version\Version;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 
 class StatusCommandTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var DependencyFactory */
+    /** @var DependencyFactory|MockObject */
     private $dependencyFactory;
 
-    /** @var MigrationRepository */
+    /** @var MigrationRepository|MockObject */
     private $migrationRepository;
 
-    /** @var MigrationStatusInfosHelper */
+    /** @var MigrationStatusInfosHelper|MockObject */
     private $migrationStatusInfosHelper;
 
     /** @var StatusCommand */
@@ -38,11 +39,11 @@ public function testExecute() : void
         $input  = $this->createMock(InputInterface::class);
         $output = $this->createMock(OutputInterface::class);
 
-        $this->migrationStatusInfosHelper->expects($this->once())
+        $this->migrationStatusInfosHelper->expects(self::once())
             ->method('getMigrationsInfos')
             ->willReturn(['name' => 'value']);
 
-        $input->expects($this->once())
+        $input->expects(self::once())
             ->method('getOption')
             ->with('show-versions')
             ->willReturn(true);
@@ -50,89 +51,89 @@ public function testExecute() : void
         $version1   = $this->createMock(Version::class);
         $migration1 = $this->createMock(AbstractMigration::class);
 
-        $version1->expects($this->once())
+        $version1->expects(self::once())
             ->method('getVersion')
             ->willReturn('1');
 
-        $version1->expects($this->once())
+        $version1->expects(self::once())
             ->method('getMigration')
             ->willReturn($migration1);
 
-        $version1->expects($this->once())
+        $version1->expects(self::once())
             ->method('isMigrated')
             ->willReturn(true);
 
         $executedAt = new DateTimeImmutable('2018-05-16 11:14:40');
 
-        $version1->expects($this->once())
+        $version1->expects(self::once())
             ->method('getExecutedAt')
             ->willReturn($executedAt);
 
-        $migration1->expects($this->once())
+        $migration1->expects(self::once())
             ->method('getDescription')
             ->willReturn('Test description.');
 
         $version2   = $this->createMock(Version::class);
         $migration2 = $this->createMock(AbstractMigration::class);
 
-        $version2->expects($this->once())
+        $version2->expects(self::once())
             ->method('getVersion')
             ->willReturn('2');
 
-        $version2->expects($this->once())
+        $version2->expects(self::once())
             ->method('getMigration')
             ->willReturn($migration2);
 
-        $version2->expects($this->once())
+        $version2->expects(self::once())
             ->method('isMigrated')
             ->willReturn(false);
 
-        $version2->expects($this->once())
+        $version2->expects(self::once())
             ->method('getExecutedAt')
             ->willReturn(null);
 
-        $migration2->expects($this->once())
+        $migration2->expects(self::once())
             ->method('getDescription')
             ->willReturn('Test description.');
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getMigrations')
             ->willReturn([$version1, $version2]);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getExecutedUnavailableMigrations')
             ->willReturn(['1234']);
 
-        $this->configuration->expects($this->at(0))
+        $this->configuration->expects(self::at(0))
             ->method('getDateTime')
             ->with('1234')
             ->willReturn('123456789');
 
-        $output->expects($this->at(0))
+        $output->expects(self::at(0))
             ->method('writeln')
             ->with("\n <info>==</info> Configuration\n");
 
-        $output->expects($this->at(1))
+        $output->expects(self::at(1))
             ->method('writeln')
             ->with('    <comment>>></comment> name:                                               value');
 
-        $output->expects($this->at(2))
+        $output->expects(self::at(2))
             ->method('writeln')
             ->with("\n <info>==</info> Available Migration Versions\n");
 
-        $output->expects($this->at(3))
+        $output->expects(self::at(3))
             ->method('writeln')
             ->with('    <comment>>></comment>  (<comment>1</comment>)                                                <info>migrated</info> (executed at 2018-05-16 11:14:40)     Test description.');
 
-        $output->expects($this->at(4))
+        $output->expects(self::at(4))
             ->method('writeln')
             ->with('    <comment>>></comment>  (<comment>2</comment>)                                                <error>not migrated</error>     Test description.');
 
-        $output->expects($this->at(5))
+        $output->expects(self::at(5))
             ->method('writeln')
             ->with("\n <info>==</info> Previously Executed Unavailable Migration Versions\n");
 
-        $output->expects($this->at(6))
+        $output->expects(self::at(6))
             ->method('writeln')
             ->with('    <comment>>></comment> 123456789 (<comment>1234</comment>)');
 
@@ -146,7 +147,7 @@ protected function setUp() : void
         $this->migrationRepository        = $this->createMock(MigrationRepository::class);
         $this->migrationStatusInfosHelper = $this->createMock(MigrationStatusInfosHelper::class);
 
-        $this->dependencyFactory->expects($this->once())
+        $this->dependencyFactory->expects(self::once())
             ->method('getMigrationStatusInfosHelper')
             ->willReturn($this->migrationStatusInfosHelper);
 
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/UpToDateCommandTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/UpToDateCommandTest.php
index 7275e593e5..6153f6be69 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Command/UpToDateCommandTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Command/UpToDateCommandTest.php
@@ -7,13 +7,14 @@
 use Doctrine\Migrations\MigrationRepository;
 use Doctrine\Migrations\Tools\Console\Command\UpToDateCommand;
 use Doctrine\Migrations\Version\Version;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Console\Input\ArrayInput;
 use Symfony\Component\Console\Output\OutputInterface;
 
 class UpToDateCommandTest extends TestCase
 {
-    /** @var MigrationRepository */
+    /** @var MigrationRepository|MockObject */
     private $migrationRepository;
 
     /** @var UpToDateCommand */
@@ -45,7 +46,7 @@ public function testIsUpToDate(array $migrations, array $migratedVersions, int $
 
         $output = $this->createMock(OutputInterface::class);
 
-        $output->expects($this->once())
+        $output->expects(self::once())
             ->method('writeln');
 
         $actual = $this->upToDateCommand->execute(new ArrayInput([]), $output);
@@ -54,7 +55,7 @@ public function testIsUpToDate(array $migrations, array $migratedVersions, int $
     }
 
     /**
-     * @return string[][]
+     * @return mixed[][]
      */
     public function dataIsUpToDate() : array
     {
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/ConnectionLoaderTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/ConnectionLoaderTest.php
index 83ae396ac8..19e63b6888 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/ConnectionLoaderTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/ConnectionLoaderTest.php
@@ -9,16 +9,17 @@
 use Doctrine\Migrations\Configuration\Connection\ConnectionLoaderInterface;
 use Doctrine\Migrations\Configuration\Connection\Loader\ConnectionConfigurationChainLoader;
 use Doctrine\Migrations\Tools\Console\ConnectionLoader;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Console\Helper\HelperSet;
 use Symfony\Component\Console\Input\InputInterface;
 
 class ConnectionLoaderTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var ConnectionConfigurationChainLoader */
+    /** @var ConnectionConfigurationChainLoader|MockObject */
     private $connectionConfigurationChainLoader;
 
     /** @var ConnectionLoader */
@@ -30,7 +31,7 @@ public function testGetConnection() : void
         $helperSet  = $this->createMock(HelperSet::class);
         $connection = $this->createMock(Connection::class);
 
-        $this->connectionConfigurationChainLoader->expects($this->once())
+        $this->connectionConfigurationChainLoader->expects(self::once())
             ->method('chosen')
             ->wilLReturn($connection);
 
@@ -50,7 +51,7 @@ protected function setUp() : void
             ConnectionLoaderInterface::class
         );
 
-        $this->connectionLoader->expects($this->once())
+        $this->connectionLoader->expects(self::once())
             ->method('createConnectionConfigurationChainLoader')
             ->willReturn($this->connectionConfigurationChainLoader);
     }
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/ConsoleRunnerTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/ConsoleRunnerTest.php
index 44037d64e7..fc28aa4435 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/ConsoleRunnerTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/ConsoleRunnerTest.php
@@ -9,6 +9,7 @@
 use PHPUnit\Framework\TestCase;
 use PHPUnit_Framework_MockObject_MockObject;
 use Symfony\Component\Console\Application;
+use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Helper\HelperSet;
 
 /**
@@ -30,7 +31,7 @@ public function testRun() : void
 
         ConsoleRunnerStub::$application = $application;
 
-        $application->expects($this->once())
+        $application->expects(self::once())
             ->method('run');
 
         ConsoleRunnerStub::run($helperSet, []);
@@ -107,9 +108,11 @@ public function testNotHasDiffCommand() : void
 
     public function testCreateApplication() : void
     {
-        $actual = ConsoleRunner::createApplication(new HelperSet());
+        $helperSet = new HelperSet();
 
-        self::assertInstanceOf(Application::class, $actual);
+        $application = ConsoleRunner::createApplication($helperSet);
+
+        self::assertSame($helperSet, $application->getHelperSet());
     }
 
     protected function setUp() : void
@@ -125,10 +128,12 @@ protected function setUp() : void
 
 class ConsoleRunnerStub extends ConsoleRunner
 {
-    /** @var Application|null */
+    /** @var Application */
     public static $application;
 
-    /** @param AbstractCommand[] $commands */
+    /**
+     * @param Command[] $commands
+     */
     public static function createApplication(HelperSet $helperSet, array $commands = []) : Application
     {
         return static::$application;
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/ConfigurationHelperTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/ConfigurationHelperTest.php
index 3f45de9dbf..c775736414 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/ConfigurationHelperTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/ConfigurationHelperTest.php
@@ -6,17 +6,14 @@
 
 use Doctrine\DBAL\Connection;
 use Doctrine\Migrations\Configuration\ArrayConfiguration;
-use Doctrine\Migrations\Configuration\Configuration;
 use Doctrine\Migrations\Configuration\JsonConfiguration;
-use Doctrine\Migrations\OutputWriter;
 use Doctrine\Migrations\Tests\MigrationTestCase;
 use Doctrine\Migrations\Tools\Console\Helper\ConfigurationHelper;
-use Doctrine\ORM\Configuration as ORMConfiguration;
 use InvalidArgumentException;
-use PHPUnit_Framework_MockObject_MockObject;
+use PHPUnit\Framework\MockObject\MockObject;
 use Symfony\Component\Console\Input\ArrayInput;
 use Symfony\Component\Console\Input\InputInterface;
-use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Output\StreamOutput;
 use function copy;
 use function trim;
 use function unlink;
@@ -26,22 +23,14 @@ class ConfigurationHelperTest extends MigrationTestCase
     /** @var Connection */
     private $connection;
 
-    /** @var ORMConfiguration */
-    private $configuration;
-
-    /** @var OutputWriter */
-    protected $outputWriter;
-
-    /** @var OutputInterface */
+    /** @var StreamOutput */
     protected $output;
 
-    /** @var InputInterface|PHPUnit_Framework_MockObject_MockObject */
+    /** @var InputInterface|MockObject */
     private $input;
 
     protected function setUp() : void
     {
-        $this->configuration = $this->getSqliteConfiguration();
-
         $this->connection = $this->getSqliteConnection();
 
         $this->output = $this->getOutputStream();
@@ -52,13 +41,6 @@ protected function setUp() : void
             ->getMock();
     }
 
-    public function testConfigurationHelper() : void
-    {
-        $configurationHelper = new ConfigurationHelper($this->connection, $this->configuration);
-
-        self::assertInstanceOf(ConfigurationHelper::class, $configurationHelper);
-    }
-
     /**
      * Used in other tests to see if xml or yaml or yml config files are loaded.
      */
@@ -72,7 +54,7 @@ protected function getConfigurationHelperLoadsASpecificFormat(
 
             $this->input->method('getOption')
                 ->with('configuration')
-                ->will($this->returnValue(null));
+                ->will(self::returnValue(null));
 
             $configurationHelper = new ConfigurationHelper($this->getSqliteConnection());
             $configfileLoaded    = $configurationHelper->getMigrationConfig($this->input);
@@ -87,7 +69,7 @@ public function testConfigurationHelperLoadsPhpArrayFormatFromCommandLine() : vo
     {
         $this->input->method('getOption')
             ->with('configuration')
-            ->will($this->returnValue(__DIR__ . '/files/config.php'));
+            ->will(self::returnValue(__DIR__ . '/files/config.php'));
 
         $configurationHelper = new ConfigurationHelper($this->getSqliteConnection());
         $migrationConfig     = $configurationHelper->getMigrationConfig($this->input);
@@ -100,7 +82,7 @@ public function testConfigurationHelperLoadsJsonFormatFromCommandLine() : void
     {
         $this->input->method('getOption')
             ->with('configuration')
-            ->will($this->returnValue(__DIR__ . '/files/config.json'));
+            ->will(self::returnValue(__DIR__ . '/files/config.json'));
 
         $configurationHelper = new ConfigurationHelper($this->getSqliteConnection());
         $migrationConfig     = $configurationHelper->getMigrationConfig($this->input);
@@ -116,7 +98,7 @@ public function testConfigurationHelperFailsToLoadOtherFormat() : void
     {
         $this->input->method('getOption')
             ->with('configuration')
-            ->will($this->returnValue('testconfig.wrong'));
+            ->will(self::returnValue('testconfig.wrong'));
 
         $configurationHelper = new ConfigurationHelper($this->getSqliteConnection());
 
@@ -130,13 +112,12 @@ public function testConfigurationHelperWithoutConfigurationFromSetterAndWithoutO
     {
         $this->input->method('getOption')
             ->with('configuration')
-            ->will($this->returnValue(null));
+            ->will(self::returnValue(null));
 
         $configurationHelper = new ConfigurationHelper($this->connection, null);
 
         $migrationConfig = $configurationHelper->getMigrationConfig($this->input);
 
-        self::assertInstanceOf(Configuration::class, $migrationConfig);
         self::assertStringMatchesFormat('', $this->getOutputStreamContent($this->output));
     }
 }
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/MigrationDirectoryHelperTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/MigrationDirectoryHelperTest.php
index fdb092ddcd..9599d8730e 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/MigrationDirectoryHelperTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/MigrationDirectoryHelperTest.php
@@ -12,13 +12,6 @@
 
 class MigrationDirectoryHelperTest extends MigrationTestCase
 {
-    public function testMigrationDirectoryHelper() : void
-    {
-        $mirationDirectoryHelper = new MigrationDirectoryHelper($this->getSqliteConfiguration());
-
-        self::assertInstanceOf(MigrationDirectoryHelper::class, $mirationDirectoryHelper);
-    }
-
     public function testMigrationDirectoryHelperReturnConfiguredDir() : void
     {
         $mirationDirectoryHelper = new MigrationDirectoryHelper($this->getSqliteConfiguration());
diff --git a/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/MigrationStatusInfosHelperTest.php b/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/MigrationStatusInfosHelperTest.php
index c880f45c47..ee9d515775 100644
--- a/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/MigrationStatusInfosHelperTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tools/Console/Helper/MigrationStatusInfosHelperTest.php
@@ -9,57 +9,61 @@
 use Doctrine\Migrations\Configuration\Configuration;
 use Doctrine\Migrations\MigrationRepository;
 use Doctrine\Migrations\Tools\Console\Helper\MigrationStatusInfosHelper;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 class MigrationStatusInfosHelperTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var Connection */
+    /** @var Connection|MockObject */
     private $connection;
 
-    /** @var Driver */
+    /** @var Driver|MockObject */
     private $driver;
 
+    /** @var MigrationRepository|MockObject */
+    private $migrationRepository;
+
     /** @var MigrationStatusInfosHelper */
     private $migrationStatusInfosHelper;
 
     public function testGetMigrationsInfos() : void
     {
-        $this->driver->expects($this->once())
+        $this->driver->expects(self::once())
             ->method('getName')
             ->willReturn('pdo_mysql');
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('getHost')
             ->willReturn('localhost');
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('getDatabase')
             ->willReturn('dbname');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getMigrationsTableName')
             ->willReturn('table_name');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getMigrationsColumnName')
             ->willReturn('column_name');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getMigrationsNamespace')
             ->willReturn('Doctrine');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('getMigrationsDirectory')
             ->willReturn('/path/to/migrations');
 
-        $this->configuration->expects($this->any())
+        $this->configuration->expects(self::any())
             ->method('resolveVersionAlias')
             ->willReturn('001');
 
-        $this->configuration->expects($this->any())
+        $this->configuration->expects(self::any())
             ->method('getDateTime')
             ->willReturn('2017-09-01 01:01:01');
 
@@ -95,15 +99,15 @@ protected function setUp() : void
         $this->connection          = $this->createMock(Connection::class);
         $this->driver              = $this->createMock(Driver::class);
 
-        $this->configuration->expects($this->any())
+        $this->configuration->expects(self::any())
             ->method('getConnection')
             ->willReturn($this->connection);
 
-        $this->connection->expects($this->any())
+        $this->connection->expects(self::any())
             ->method('getDriver')
             ->willReturn($this->driver);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getMigratedVersions')
             ->willReturn([
                 '001',
@@ -111,7 +115,7 @@ protected function setUp() : void
                 '003',
             ]);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getAvailableVersions')
             ->willReturn([
                 '001',
@@ -119,11 +123,11 @@ protected function setUp() : void
                 '004',
             ]);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getNewVersions')
             ->willReturn(['004']);
 
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('getExecutedUnavailableMigrations')
             ->willReturn(['001']);
 
diff --git a/tests/Doctrine/Migrations/Tests/Tracking/TableDefinitionTest.php b/tests/Doctrine/Migrations/Tests/Tracking/TableDefinitionTest.php
index 734f7560ec..b7367076b9 100644
--- a/tests/Doctrine/Migrations/Tests/Tracking/TableDefinitionTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tracking/TableDefinitionTest.php
@@ -7,11 +7,12 @@
 use Doctrine\DBAL\Schema\AbstractSchemaManager;
 use Doctrine\DBAL\Schema\SchemaConfig;
 use Doctrine\Migrations\Tracking\TableDefinition;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 class TableDefinitionTest extends TestCase
 {
-    /** @var AbstractSchemaManager */
+    /** @var AbstractSchemaManager|MockObject */
     private $schemaManager;
 
     /** @var TableDefinition */
@@ -62,11 +63,11 @@ public function testGetDBALTable() : void
     {
         $schemaConfig = $this->createMock(SchemaConfig::class);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('createSchemaConfig')
             ->willReturn($schemaConfig);
 
-        $schemaConfig->expects($this->once())
+        $schemaConfig->expects(self::once())
             ->method('getDefaultTableOptions')
             ->willReturn(['test_option' => true]);
 
@@ -75,7 +76,7 @@ public function testGetDBALTable() : void
         self::assertCount(2, $table->getColumns());
 
         self::assertTrue($table->hasOption('test_option'));
-        self::assertSame(true, $table->getOption('test_option'));
+        self::assertTrue($table->getOption('test_option'));
 
         self::assertTrue($table->hasColumn('version_name'));
         self::assertTrue($table->getColumn('version_name')->getNotnull());
@@ -88,11 +89,11 @@ public function testGetNewDBALTable() : void
     {
         $schemaConfig = $this->createMock(SchemaConfig::class);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('createSchemaConfig')
             ->willReturn($schemaConfig);
 
-        $schemaConfig->expects($this->once())
+        $schemaConfig->expects(self::once())
             ->method('getDefaultTableOptions')
             ->willReturn(['test_option' => true]);
 
@@ -101,7 +102,7 @@ public function testGetNewDBALTable() : void
         self::assertCount(2, $table->getColumns());
 
         self::assertTrue($table->hasOption('test_option'));
-        self::assertSame(true, $table->getOption('test_option'));
+        self::assertTrue($table->getOption('test_option'));
 
         self::assertTrue($table->hasColumn('version_name'));
         self::assertTrue($table->getColumn('version_name')->getNotnull());
diff --git a/tests/Doctrine/Migrations/Tests/Tracking/TableManipulatorTest.php b/tests/Doctrine/Migrations/Tests/Tracking/TableManipulatorTest.php
index 989c21a456..95971e75de 100644
--- a/tests/Doctrine/Migrations/Tests/Tracking/TableManipulatorTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tracking/TableManipulatorTest.php
@@ -11,23 +11,24 @@
 use Doctrine\Migrations\Tracking\TableManipulator;
 use Doctrine\Migrations\Tracking\TableStatus;
 use Doctrine\Migrations\Tracking\TableUpdater;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 class TableManipulatorTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var AbstractSchemaManager */
+    /** @var AbstractSchemaManager|MockObject */
     private $schemaManager;
 
-    /** @var TableDefinition */
+    /** @var TableDefinition|MockObject */
     private $migrationTable;
 
-    /** @var TableStatus */
+    /** @var TableStatus|MockObject */
     private $migrationTableStatus;
 
-    /** @var TableUpdater */
+    /** @var TableUpdater|MockObject */
     private $migrationTableUpdater;
 
     /** @var TableManipulator */
@@ -35,18 +36,18 @@ class TableManipulatorTest extends TestCase
 
     public function testCreateMigrationTableAlreadyCreated() : void
     {
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('validate');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('isDryRun')
             ->willReturn(false);
 
-        $this->migrationTableStatus->expects($this->once())
+        $this->migrationTableStatus->expects(self::once())
             ->method('isCreated')
             ->willReturn(true);
 
-        $this->migrationTableStatus->expects($this->once())
+        $this->migrationTableStatus->expects(self::once())
             ->method('isUpToDate')
             ->willReturn(true);
 
@@ -66,25 +67,25 @@ public function testCreateMigrationTableNotUpToDate() : void
             ->setMethods(['createSchema'])
             ->getMock();
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('validate');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('isDryRun')
             ->willReturn(false);
 
-        $this->migrationTableStatus->expects($this->once())
+        $this->migrationTableStatus->expects(self::once())
             ->method('isCreated')
             ->willReturn(true);
 
-        $this->migrationTableStatus->expects($this->once())
+        $this->migrationTableStatus->expects(self::once())
             ->method('isUpToDate')
             ->willReturn(false);
 
-        $this->migrationTableUpdater->expects($this->once())
+        $this->migrationTableUpdater->expects(self::once())
             ->method('updateMigrationTable');
 
-        $this->migrationTableStatus->expects($this->once())
+        $this->migrationTableStatus->expects(self::once())
             ->method('setUpToDate')
             ->with(true);
 
@@ -93,24 +94,24 @@ public function testCreateMigrationTableNotUpToDate() : void
 
     public function testCreateMigrationTable() : void
     {
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('validate');
 
-        $this->configuration->expects($this->once())
+        $this->configuration->expects(self::once())
             ->method('isDryRun')
             ->willReturn(false);
 
-        $this->migrationTableStatus->expects($this->once())
+        $this->migrationTableStatus->expects(self::once())
             ->method('isCreated')
             ->willReturn(false);
 
         $table = $this->createMock(Table::class);
 
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getNewDBALTable')
             ->willReturn($table);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('createTable')
             ->with($table);
 
diff --git a/tests/Doctrine/Migrations/Tests/Tracking/TableStatusTest.php b/tests/Doctrine/Migrations/Tests/Tracking/TableStatusTest.php
index 55e0d08e0c..67d393d92c 100644
--- a/tests/Doctrine/Migrations/Tests/Tracking/TableStatusTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tracking/TableStatusTest.php
@@ -8,14 +8,15 @@
 use Doctrine\DBAL\Schema\Table;
 use Doctrine\Migrations\Tracking\TableDefinition;
 use Doctrine\Migrations\Tracking\TableStatus;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 class TableStatusTest extends TestCase
 {
-    /** @var AbstractSchemaManager */
+    /** @var AbstractSchemaManager|MockObject */
     private $schemaManager;
 
-    /** @var TableDefinition */
+    /** @var TableDefinition|MockObject */
     private $migrationTable;
 
     /** @var TableStatus */
@@ -30,11 +31,11 @@ public function testSetCreated() : void
 
     public function testIsCreatedTrue() : void
     {
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getName')
             ->willReturn('table_name');
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('tablesExist')
             ->with(['table_name'])
             ->willReturn(true);
@@ -44,11 +45,11 @@ public function testIsCreatedTrue() : void
 
     public function testIsCreatedFalse() : void
     {
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getName')
             ->willReturn('table_name');
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('tablesExist')
             ->with(['table_name'])
             ->willReturn(false);
@@ -58,75 +59,75 @@ public function testIsCreatedFalse() : void
 
     public function testSetUpToDate() : void
     {
-        $this->migrationTableStatus->setUpTodate(true);
+        $this->migrationTableStatus->setUpToDate(true);
 
         self::assertTrue($this->migrationTableStatus->isUpToDate());
     }
 
     public function testIsUpToDateTrue() : void
     {
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getName')
             ->willReturn('table_name');
 
         $table = $this->createMock(Table::class);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('listTableDetails')
             ->with('table_name')
             ->willReturn($table);
 
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getColumnNames')
             ->willReturn([
                 'version',
                 'executed_at',
             ]);
 
-        $table->expects($this->at(0))
+        $table->expects(self::at(0))
             ->method('hasColumn')
             ->with('version')
             ->willReturn(true);
 
-        $table->expects($this->at(1))
+        $table->expects(self::at(1))
             ->method('hasColumn')
             ->with('executed_at')
             ->willReturn(true);
 
-        self::assertTrue($this->migrationTableStatus->isUpTodate());
+        self::assertTrue($this->migrationTableStatus->isUpToDate());
     }
 
     public function testIsUpToDateFalse() : void
     {
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getName')
             ->willReturn('table_name');
 
         $table = $this->createMock(Table::class);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('listTableDetails')
             ->with('table_name')
             ->willReturn($table);
 
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getColumnNames')
             ->willReturn([
                 'version',
                 'executed_at',
             ]);
 
-        $table->expects($this->at(0))
+        $table->expects(self::at(0))
             ->method('hasColumn')
             ->with('version')
             ->willReturn(true);
 
-        $table->expects($this->at(1))
+        $table->expects(self::at(1))
             ->method('hasColumn')
             ->with('executed_at')
             ->willReturn(false);
 
-        self::assertFalse($this->migrationTableStatus->isUpTodate());
+        self::assertFalse($this->migrationTableStatus->isUpToDate());
     }
 
     protected function setUp() : void
diff --git a/tests/Doctrine/Migrations/Tests/Tracking/TableUpdaterTest.php b/tests/Doctrine/Migrations/Tests/Tracking/TableUpdaterTest.php
index 271b4946b1..45467f8a10 100644
--- a/tests/Doctrine/Migrations/Tests/Tracking/TableUpdaterTest.php
+++ b/tests/Doctrine/Migrations/Tests/Tracking/TableUpdaterTest.php
@@ -14,33 +14,34 @@
 use Doctrine\Migrations\Tracking\TableDefinition;
 use Doctrine\Migrations\Tracking\TableUpdater;
 use Exception;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Throwable;
 
 class TableUpdaterTest extends TestCase
 {
-    /** @var Connection */
+    /** @var Connection|MockObject */
     private $connection;
 
-    /** @var AbstractSchemaManager */
+    /** @var AbstractSchemaManager|MockObject */
     private $schemaManager;
 
-    /** @var TableDefinition */
+    /** @var TableDefinition|MockObject */
     private $migrationTable;
 
-    /** @var AbstractPlatform */
+    /** @var AbstractPlatform|MockObject */
     private $platform;
 
-    /** @var TableUpdater */
+    /** @var TableUpdater|MockObject */
     private $migrationTableUpdater;
 
     public function testUpdateMigrationTable() : void
     {
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getName')
             ->willReturn('table_name');
 
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getColumnNames')
             ->willReturn([
                 'version',
@@ -49,7 +50,7 @@ public function testUpdateMigrationTable() : void
 
         $table = $this->createMock(Table::class);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('listTableDetails')
             ->willReturn($table);
 
@@ -64,7 +65,7 @@ public function testUpdateMigrationTable() : void
             Type::getType('datetime_immutable')
         );
 
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('createDBALTable')
             ->with([
                 $versionColumn,
@@ -72,7 +73,7 @@ public function testUpdateMigrationTable() : void
             ])
             ->willReturn($table);
 
-        $table->expects($this->any())
+        $table->expects(self::any())
             ->method('getColumns')
             ->willReturn([
                 $versionColumn,
@@ -82,27 +83,27 @@ public function testUpdateMigrationTable() : void
         $fromSchema = $this->createMock(Schema::class);
         $toSchema   = $this->createMock(Schema::class);
 
-        $this->migrationTableUpdater->expects($this->at(0))
+        $this->migrationTableUpdater->expects(self::at(0))
             ->method('createSchema')
             ->willReturn($fromSchema);
 
-        $this->migrationTableUpdater->expects($this->at(1))
+        $this->migrationTableUpdater->expects(self::at(1))
             ->method('createSchema')
             ->willReturn($toSchema);
 
-        $fromSchema->expects($this->once())
+        $fromSchema->expects(self::once())
             ->method('getMigrateToSql')
             ->with($toSchema, $this->platform)
             ->willReturn(['ALTER TABLE table_name ADD COLUMN executed_at DATETIME DEFAULT NULL']);
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('beginTransaction');
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('executeQuery')
             ->with('ALTER TABLE table_name ADD COLUMN executed_at DATETIME DEFAULT NULL');
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('commit');
 
         $this->migrationTableUpdater->updateMigrationTable();
@@ -113,11 +114,11 @@ public function testUpdateMigrationTableRollback() : void
         $this->expectException(Throwable::class);
         $this->expectExceptionMessage('Rolling back.');
 
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getName')
             ->willReturn('table_name');
 
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('getColumnNames')
             ->willReturn([
                 'version',
@@ -126,7 +127,7 @@ public function testUpdateMigrationTableRollback() : void
 
         $table = $this->createMock(Table::class);
 
-        $this->schemaManager->expects($this->once())
+        $this->schemaManager->expects(self::once())
             ->method('listTableDetails')
             ->willReturn($table);
 
@@ -141,7 +142,7 @@ public function testUpdateMigrationTableRollback() : void
             Type::getType('datetime_immutable')
         );
 
-        $this->migrationTable->expects($this->once())
+        $this->migrationTable->expects(self::once())
             ->method('createDBALTable')
             ->with([
                 $versionColumn,
@@ -149,7 +150,7 @@ public function testUpdateMigrationTableRollback() : void
             ])
             ->willReturn($table);
 
-        $table->expects($this->any())
+        $table->expects(self::any())
             ->method('getColumns')
             ->willReturn([
                 $versionColumn,
@@ -159,28 +160,28 @@ public function testUpdateMigrationTableRollback() : void
         $fromSchema = $this->createMock(Schema::class);
         $toSchema   = $this->createMock(Schema::class);
 
-        $this->migrationTableUpdater->expects($this->at(0))
+        $this->migrationTableUpdater->expects(self::at(0))
             ->method('createSchema')
             ->willReturn($fromSchema);
 
-        $this->migrationTableUpdater->expects($this->at(1))
+        $this->migrationTableUpdater->expects(self::at(1))
             ->method('createSchema')
             ->willReturn($toSchema);
 
-        $fromSchema->expects($this->once())
+        $fromSchema->expects(self::once())
             ->method('getMigrateToSql')
             ->with($toSchema, $this->platform)
             ->willReturn(['ALTER TABLE table_name ADD COLUMN executed_at DATETIME DEFAULT NULL']);
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('beginTransaction');
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('executeQuery')
             ->with('ALTER TABLE table_name ADD COLUMN executed_at DATETIME DEFAULT NULL')
             ->willThrowException(new Exception('Rolling back.'));
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('rollback');
 
         $this->migrationTableUpdater->updateMigrationTable();
diff --git a/tests/Doctrine/Migrations/Tests/Version/AliasResolverTest.php b/tests/Doctrine/Migrations/Tests/Version/AliasResolverTest.php
index bdc692ebb8..d2c105a135 100644
--- a/tests/Doctrine/Migrations/Tests/Version/AliasResolverTest.php
+++ b/tests/Doctrine/Migrations/Tests/Version/AliasResolverTest.php
@@ -6,11 +6,12 @@
 
 use Doctrine\Migrations\MigrationRepository;
 use Doctrine\Migrations\Version\AliasResolver;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
 final class AliasResolverTest extends TestCase
 {
-    /** @var MigrationRepository */
+    /** @var MigrationRepository|MockObject */
     private $migrationRepository;
 
     /** @var AliasResolver */
@@ -25,17 +26,17 @@ public function testResolveVersionAlias(
         ?string $expectedMethod,
         ?string $expectedArgument
     ) : void {
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('hasVersion')
             ->with($alias)
             ->willReturn(false);
 
         if ($expectedMethod !== null) {
-            $expectation = $this->migrationRepository->expects($this->once())
+            $expectation = $this->migrationRepository->expects(self::once())
                 ->method($expectedMethod)
                 ->willReturn($expectedVersion);
 
-            if ($expectedArgument) {
+            if ($expectedArgument !== null) {
                 $expectation->with($expectedArgument);
             }
         }
@@ -61,7 +62,7 @@ public function getAliases() : array
 
     public function testResolveVersionAliasHasVersion() : void
     {
-        $this->migrationRepository->expects($this->once())
+        $this->migrationRepository->expects(self::once())
             ->method('hasVersion')
             ->with('test')
             ->willReturn(true);
diff --git a/tests/Doctrine/Migrations/Tests/Version/ExecutionResultTest.php b/tests/Doctrine/Migrations/Tests/Version/ExecutionResultTest.php
index 4c6ce724f5..49f8f63eb1 100644
--- a/tests/Doctrine/Migrations/Tests/Version/ExecutionResultTest.php
+++ b/tests/Doctrine/Migrations/Tests/Version/ExecutionResultTest.php
@@ -10,6 +10,9 @@
 
 class ExecutionResultTest extends TestCase
 {
+    /** @var ExecutionResult */
+    private $versionExecutionResult;
+
     public function testHasSql() : void
     {
         self::assertTrue($this->versionExecutionResult->hasSql());
@@ -78,10 +81,13 @@ public function testError() : void
         self::assertTrue($this->versionExecutionResult->hasError());
     }
 
-    public function testException() : void
+    public function testExceptionNull() : void
     {
         self::assertNull($this->versionExecutionResult->getException());
+    }
 
+    public function testException() : void
+    {
         $exception = new InvalidArgumentException();
 
         $this->versionExecutionResult->setException($exception);
diff --git a/tests/Doctrine/Migrations/Tests/Version/ExecutorTest.php b/tests/Doctrine/Migrations/Tests/Version/ExecutorTest.php
index 8a1a1c3f06..ff26d3840a 100644
--- a/tests/Doctrine/Migrations/Tests/Version/ExecutorTest.php
+++ b/tests/Doctrine/Migrations/Tests/Version/ExecutorTest.php
@@ -16,30 +16,30 @@
 use Doctrine\Migrations\Provider\SchemaDiffProviderInterface;
 use Doctrine\Migrations\Stopwatch;
 use Doctrine\Migrations\Version\Direction;
-use Doctrine\Migrations\Version\ExecutionResult;
 use Doctrine\Migrations\Version\Executor;
 use Doctrine\Migrations\Version\Version;
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Stopwatch\StopwatchEvent;
 
 class ExecutorTest extends TestCase
 {
-    /** @var Configuration */
+    /** @var Configuration|MockObject */
     private $configuration;
 
-    /** @var Connection */
+    /** @var Connection|MockObject */
     private $connection;
 
-    /** @var SchemaDiffProviderInterface */
+    /** @var SchemaDiffProviderInterface|MockObject */
     private $schemaDiffProvider;
 
-    /** @var OutputWriter */
+    /** @var OutputWriter|MockObject */
     private $outputWriter;
 
-    /** @var ParameterFormatter */
+    /** @var ParameterFormatter|MockObject */
     private $parameterFormatter;
 
-    /** @var Stopwatch */
+    /** @var Stopwatch|MockObject */
     private $stopwatch;
 
     /** @var Executor */
@@ -48,7 +48,7 @@ class ExecutorTest extends TestCase
     /** @var Version */
     private $version;
 
-    /** @var AbstractMigration */
+    /** @var VersionExecutorTestMigration */
     private $migration;
 
     public function testAddSql() : void
@@ -64,48 +64,48 @@ public function testExecuteUp() : void
     {
         $platform = $this->createMock(AbstractPlatform::class);
 
-        $this->connection->expects($this->once())
+        $this->connection->expects(self::once())
             ->method('getDatabasePlatform')
             ->willReturn($platform);
 
         $stopwatchEvent = $this->createMock(StopwatchEvent::class);
 
-        $this->stopwatch->expects($this->any())
+        $this->stopwatch->expects(self::any())
             ->method('start')
             ->willReturn($stopwatchEvent);
 
-        $stopwatchEvent->expects($this->any())
+        $stopwatchEvent->expects(self::any())
             ->method('stop');
 
-        $stopwatchEvent->expects($this->any())
+        $stopwatchEvent->expects(self::any())
             ->method('getDuration')
             ->willReturn(100);
 
-        $stopwatchEvent->expects($this->any())
+        $stopwatchEvent->expects(self::any())
             ->method('getMemory')
             ->willReturn(100);
 
-        $this->outputWriter->expects($this->at(0))
+        $this->outputWriter->expects(self::at(0))
             ->method('write')
             ->with("\n  <info>++</info> migrating <comment>001</comment>\n");
 
-        $this->outputWriter->expects($this->at(1))
+        $this->outputWriter->expects(self::at(1))
             ->method('write')
             ->with('     <comment>-></comment> SELECT 1');
 
-        $this->outputWriter->expects($this->at(2))
+        $this->outputWriter->expects(self::at(2))
             ->method('write')
             ->with('  <info>100ms</info>');
 
-        $this->outputWriter->expects($this->at(3))
+        $this->outputWriter->expects(self::at(3))
             ->method('write')
             ->with('     <comment>-></comment> SELECT 2');
 
-        $this->outputWriter->expects($this->at(4))
+        $this->outputWriter->expects(self::at(4))
             ->method('write')
             ->with('  <info>100ms</info>');
 
-        $this->outputWriter->expects($this->at(5))
+        $this->outputWriter->expects(self::at(5))
             ->method('write')
             ->with("\n  <info>++</info> migrated (took 100ms, used 100 memory)");
 
@@ -119,7 +119,6 @@ public function testExecuteUp() : void
             $migratorConfiguration
         );
 
-        self::assertInstanceOf(ExecutionResult::class, $versionExecutionResult);
         self::assertSame(['SELECT 1', 'SELECT 2'], $versionExecutionResult->getSql());
         self::assertSame([[1], [2]], $versionExecutionResult->getParams());
         self::assertSame([[3], [4]], $versionExecutionResult->getTypes());
@@ -135,42 +134,42 @@ public function testExecuteDown() : void
     {
         $stopwatchEvent = $this->createMock(StopwatchEvent::class);
 
-        $this->stopwatch->expects($this->any())
+        $this->stopwatch->expects(self::any())
             ->method('start')
             ->willReturn($stopwatchEvent);
 
-        $stopwatchEvent->expects($this->any())
+        $stopwatchEvent->expects(self::any())
             ->method('stop');
 
-        $stopwatchEvent->expects($this->any())
+        $stopwatchEvent->expects(self::any())
             ->method('getDuration')
             ->willReturn(100);
 
-        $stopwatchEvent->expects($this->any())
+        $stopwatchEvent->expects(self::any())
             ->method('getMemory')
             ->willReturn(100);
 
-        $this->outputWriter->expects($this->at(0))
+        $this->outputWriter->expects(self::at(0))
             ->method('write')
             ->with("\n  <info>--</info> reverting <comment>001</comment>\n");
 
-        $this->outputWriter->expects($this->at(1))
+        $this->outputWriter->expects(self::at(1))
             ->method('write')
             ->with('     <comment>-></comment> SELECT 3');
 
-        $this->outputWriter->expects($this->at(2))
+        $this->outputWriter->expects(self::at(2))
             ->method('write')
             ->with('  <info>100ms</info>');
 
-        $this->outputWriter->expects($this->at(3))
+        $this->outputWriter->expects(self::at(3))
             ->method('write')
             ->with('     <comment>-></comment> SELECT 4');
 
-        $this->outputWriter->expects($this->at(4))
+        $this->outputWriter->expects(self::at(4))
             ->method('write')
             ->with('  <info>100ms</info>');
 
-        $this->outputWriter->expects($this->at(5))
+        $this->outputWriter->expects(self::at(5))
             ->method('write')
             ->with("\n  <info>--</info> reverted (took 100ms, used 100 memory)");
 
@@ -184,7 +183,6 @@ public function testExecuteDown() : void
             $migratorConfiguration
         );
 
-        self::assertInstanceOf(ExecutionResult::class, $versionExecutionResult);
         self::assertSame(['SELECT 3', 'SELECT 4'], $versionExecutionResult->getSql());
         self::assertSame([[5], [6]], $versionExecutionResult->getParams());
         self::assertSame([[7], [8]], $versionExecutionResult->getTypes());
@@ -214,7 +212,7 @@ protected function setUp() : void
             $this->stopwatch
         );
 
-        $this->configuration->expects($this->any())
+        $this->configuration->expects(self::any())
             ->method('getConnection')
             ->willReturn($this->connection);
 
diff --git a/tests/Doctrine/Migrations/Tests/Version/FactoryTest.php b/tests/Doctrine/Migrations/Tests/Version/FactoryTest.php
index 65ccf6537f..766aa3049e 100644
--- a/tests/Doctrine/Migrations/Tests/Version/FactoryTest.php
+++ b/tests/Doctrine/Migrations/Tests/Version/FactoryTest.php
@@ -7,10 +7,8 @@
 use Doctrine\DBAL\Schema\Schema;
 use Doctrine\Migrations\AbstractMigration;
 use Doctrine\Migrations\Configuration\Configuration;
-use Doctrine\Migrations\Tests\VersionExecutor;
 use Doctrine\Migrations\Version\ExecutorInterface;
 use Doctrine\Migrations\Version\Factory;
-use Doctrine\Migrations\Version\Version;
 use PHPUnit\Framework\TestCase;
 
 final class FactoryTest extends TestCase
@@ -18,7 +16,7 @@ final class FactoryTest extends TestCase
     /** @var Configuration */
     private $configuration;
 
-    /** @var VersionExecutor */
+    /** @var ExecutorInterface */
     private $versionExecutor;
 
     /** @var Factory */
@@ -31,7 +29,6 @@ public function testCreateVersion() : void
             VersionFactoryTestMigration::class
         );
 
-        self::assertInstanceOf(Version::class, $version);
         self::assertSame($this->configuration, $version->getConfiguration());
         self::assertInstanceOf(VersionFactoryTestMigration::class, $version->getMigration());
     }
diff --git a/tests/Doctrine/Migrations/Tests/Version/VersionTest.php b/tests/Doctrine/Migrations/Tests/Version/VersionTest.php
index e4a37850ec..4500deef20 100644
--- a/tests/Doctrine/Migrations/Tests/Version/VersionTest.php
+++ b/tests/Doctrine/Migrations/Tests/Version/VersionTest.php
@@ -83,8 +83,12 @@ public function testShowSqlStatementsParameters() : void
         $configuration = $this->getSqliteConfiguration();
         $configuration->setOutputWriter($outputWriter);
 
-        $version = $this->createTestVersion($configuration, '0004', VersionOutputSqlWithParam::class);
-        $version->getMigration()->setParam([
+        $version   = $this->createTestVersion($configuration, '0004', VersionOutputSqlWithParam::class);
+        $migration = $version->getMigration();
+
+        self::assertInstanceOf(VersionOutputSqlWithParam::class, $migration);
+
+        $migration->setParam([
             0 => 456,
             1 => 'tralala',
             2 => 456,
@@ -102,8 +106,12 @@ public function testShowSqlStatementsParametersWithTypes() : void
         $configuration = $this->getSqliteConfiguration();
         $configuration->setOutputWriter($outputWriter);
 
-        $version = $this->createTestVersion($configuration, '0004', VersionOutputSqlWithParamAndType::class);
-        $version->getMigration()->setParam([
+        $version   = $this->createTestVersion($configuration, '0004', VersionOutputSqlWithParamAndType::class);
+        $migration = $version->getMigration();
+
+        self::assertInstanceOf(VersionOutputSqlWithParamAndType::class, $migration);
+
+        $migration->setParam([
             0 => [
                 456,
                 3,
@@ -111,7 +119,7 @@ public function testShowSqlStatementsParametersWithTypes() : void
             ],
         ]);
 
-        $version->getMigration()->setType([Connection::PARAM_INT_ARRAY]);
+        $migration->setType([Connection::PARAM_INT_ARRAY]);
 
         $version->execute(Direction::UP, (new MigratorConfiguration())
             ->setDryRun(true));
@@ -156,7 +164,7 @@ public function testGetExecutionState(string $state) : void
         self::assertNotEmpty($version->getExecutionState());
     }
 
-    /** @return string[][] */
+    /** @return mixed[][] */
     public function stateProvider() : array
     {
         return [
@@ -172,16 +180,15 @@ public function testAddSql() : void
     {
         $configuration = $this->getSqliteConfiguration();
 
-        $version = $this->createTestVersion(
-            $configuration,
-            '003',
-            VersionDummy::class
-        );
+        $versionExecutor = $this->createMock(Executor::class);
+
+        $versionExecutor->expects(self::once())
+            ->method('addSql')
+            ->with('SELECT * FROM foo WHERE id = ?', [1], [PDO::PARAM_INT]);
 
-        self::assertNull($version->addSql('SELECT * FROM foo'));
-        self::assertNull($version->addSql('SELECT * FROM foo'));
-        self::assertNull($version->addSql('SELECT * FROM foo WHERE id = ?', [1]));
-        self::assertNull($version->addSql('SELECT * FROM foo WHERE id = ?', [1], [PDO::PARAM_INT]));
+        $version = new Version($configuration, '003', VersionDummy::class, $versionExecutor);
+
+        $version->addSql('SELECT * FROM foo WHERE id = ?', [1], [PDO::PARAM_INT]);
     }
 
     /**
@@ -197,7 +204,7 @@ public function testWriteSqlFile(string $path, string $direction, array $getSqlR
         $outputWriter = $this->createMock(OutputWriter::class);
         $queryWriter  = $this->createMock(QueryWriter::class);
 
-        $outputWriter->expects($this->atLeastOnce())
+        $outputWriter->expects(self::atLeastOnce())
             ->method('write');
 
         /** @var Configuration|PHPUnit_Framework_MockObject_MockObject $config */
@@ -223,7 +230,7 @@ public function testWriteSqlFile(string $path, string $direction, array $getSqlR
 
         $versionExecutionResult = new ExecutionResult($getSqlReturn);
 
-        $version->expects($this->once())
+        $version->expects(self::once())
             ->method('execute')
             ->with($direction)
             ->willReturn($versionExecutionResult);
@@ -235,7 +242,7 @@ public function testWriteSqlFile(string $path, string $direction, array $getSqlR
         self::assertTrue($version->writeSqlFile($path, $direction));
     }
 
-    /** @return string[][] */
+    /** @return mixed[][] */
     public function writeSqlFileProvider() : array
     {
         return [
@@ -375,7 +382,7 @@ public function testWriteSqlWriteToTheCorrectColumnName(
         }
     }
 
-    /** @return string[] */
+    /** @return string[][] */
     public function sqlWriteProvider() : array
     {
         return [
@@ -436,7 +443,6 @@ public function testWriteSqlFileShouldUseStandardCommentMarkerInSql() : void
         /** @var vfsStreamFile $sqlMigrationFile */
         $sqlMigrationFile = current($sqlFilesDir->getChildren());
 
-        self::assertInstanceOf(vfsStreamFile::class, $sqlMigrationFile);
         self::assertNotRegExp('/^\s*#/m', $sqlMigrationFile->getContent());
     }
 
@@ -523,7 +529,7 @@ public static function dryRunTypes() : array
             'doctrine_param' => [[[1, 2, 3, 4, 5]], [Connection::PARAM_INT_ARRAY], '[1, 2, 3, 4, 5]'],
             'doctrine_param_grouped' => [[[1, 2], [3, 4, 5]], [Connection::PARAM_INT_ARRAY, Connection::PARAM_INT_ARRAY], '[1, 2], [3, 4, 5]'],
             'boolean' => [[true], [''], '[true]'],
-            'object' => [[new stdClass('test')], [''], '[?]'],
+            'object' => [[new stdClass()], [''], '[?]'],
         ];
     }
 
@@ -547,13 +553,16 @@ public function testDryRunWithParametersOfComplexTypesCorrectFormatsParameters(
         $config = $this->getSqliteConfiguration();
         $config->setOutputWriter($ow);
 
-        $version = $this->createTestVersion(
+        $version   = $this->createTestVersion(
             $config,
             '006',
             VersionDryRunTypes::class
         );
+        $migration = $version->getMigration();
+
+        self::assertInstanceOf(VersionDryRunTypes::class, $migration);
 
-        $version->getMigration()->setParam($value, $type);
+        $migration->setParam($value, $type);
 
         $version->execute(Direction::UP, (new MigratorConfiguration())
             ->setDryRun(true));
@@ -580,7 +589,11 @@ public function testRunWithInsertNullValue() : void
             VersionDryRunTypes::class
         );
 
-        $version->getMigration()->setParam([null], []);
+        $migration = $version->getMigration();
+
+        self::assertInstanceOf(VersionDryRunTypes::class, $migration);
+
+        $migration->setParam([null], []);
 
         $version->execute(Direction::UP, (new MigratorConfiguration())
             ->setDryRun(true));
@@ -612,7 +625,12 @@ public function testExecutedAtTimeZone(string $timeZone) : void
         $now = (new DateTimeImmutable('now'))->setTimezone(new DateTimeZone('UTC'));
 
         self::assertSame($now->format('Y-m-d H:i'), date('Y-m-d H:i', strtotime($versionData['executed_at'])));
-        self::assertSame($timeZone, $version->getExecutedAt()->getTimeZone()->getName());
+
+        $executedAt = $version->getExecutedAt();
+
+        self::assertNotNull($executedAt);
+
+        self::assertSame($timeZone, $executedAt->getTimezone()->getName());
     }
 
     /**