Add CollectionTypeInferenceTest

src/Nexus/Collection/Collection.php

@@ -41,7 +41,15 @@ public function __construct(\Closure $callable, iterable $parameter = [])
         $this->innerIterator = ClosureIteratorAggregate::from($callable, ...$parameter);
     }
 
-    public static function wrap(\Closure|iterable $items): CollectionInterface
+    /**
+     * @template WKey
+     * @template W
+     *
+     * @param (\Closure(): iterable<WKey, W>)|iterable<WKey, W> $items
+     *
+     * @return self<WKey, W>
+     */
+    public static function wrap(\Closure|iterable $items): self
     {
         if ($items instanceof \Closure) {
             return new self(static fn(): \Generator => yield from $items());
@@ -76,7 +84,10 @@ public function getIterator(): \Traversable
         yield from $this->innerIterator->getIterator();
     }
 
-    public function keys(): CollectionInterface
+    /**
+     * @return self<int, TKey>
+     */
+    public function keys(): self
     {
         return new self(static function (iterable $collection): iterable {
             foreach ($collection as $key => $_) {
@@ -85,7 +96,10 @@ public function keys(): CollectionInterface
         }, [$this]);
     }
 
-    public function values(): CollectionInterface
+    /**
+     * @return self<int, T>
+     */
+    public function values(): self
     {
         return new self(static function (iterable $collection): iterable {
             foreach ($collection as $item) {

tests/Collection/CollectionTypeInferenceTest.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of the Nexus framework.
+ *
+ * (c) John Paul E. Balandan, CPA <[email protected]>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Nexus\Tests\Collection;
+
+use PHPStan\Testing\TypeInferenceTestCase;
+use PHPUnit\Framework\Attributes\CoversNothing;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Group;
+
+/**
+ * @internal
+ */
+#[CoversNothing]
+#[Group('static-analysis')]
+final class CollectionTypeInferenceTest extends TypeInferenceTestCase
+{
+    #[DataProvider('provideFileAssertsCases')]
+    public function testFileAsserts(string $assertType, string $file, mixed ...$args): void
+    {
+        $this->assertFileAsserts($assertType, $file, ...$args);
+    }
+
+    /**
+     * @return iterable<string, list<mixed>>
+     */
+    public static function provideFileAssertsCases(): iterable
+    {
+        // @phpstan-ignore generator.valueType
+        yield from self::gatherAssertTypesFromDirectory(__DIR__.'/data');
+    }
+}

tests/Collection/data/collection.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of the Nexus framework.
+ *
+ * (c) John Paul E. Balandan, CPA <[email protected]>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Nexus\Tests\Collection;
+
+use Nexus\Collection\Collection;
+
+use function PHPStan\Testing\assertType;
+
+assertType(
+    'Nexus\Collection\Collection<string, int>',
+    new Collection(static function (): iterable {
+        yield 'apple' => 1;
+    }),
+);
+assertType('Nexus\Collection\Collection<int, string>', Collection::wrap(['a', 'b', 'c']));
+assertType(
+    'Nexus\Collection\Collection<string, bool>',
+    Collection::wrap(static function (): iterable {
+        yield 'a' => true;
+
+        yield 'b' => true;
+
+        yield 'c' => false;
+    }),
+);
+assertType('Nexus\Collection\Collection<int, int>', Collection::wrap(new \ArrayIterator([1, 2])));
+
+assertType('array<int>', Collection::wrap(['a' => 1, 'b' => 2])->all(true));
+assertType('array<int, int>', Collection::wrap(['a' => 1, 'b' => 2])->all());
+
+$collection = Collection::wrap(['apples' => 10, 'bananas' => 20]);
+assertType('Nexus\Collection\Collection<int, string>', $collection->keys());
+assertType('Nexus\Collection\Collection<int, int>', $collection->values());

tests/Collection/data/iterator.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of the Nexus framework.
+ *
+ * (c) John Paul E. Balandan, CPA <[email protected]>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Nexus\Tests\Collection;
+
+use Nexus\Collection\Collection;
+use Nexus\Collection\Iterator\ClosureIteratorAggregate;
+
+use function PHPStan\Testing\assertType;
+
+assertType(
+    'Nexus\Collection\Iterator\ClosureIteratorAggregate<int, string>',
+    ClosureIteratorAggregate::from(
+        static fn(string $item): iterable => yield $item,
+        'a',
+    ),
+);
+assertType(
+    // @todo Make PHPStan understand the key is 'int'
+    'Nexus\Collection\Iterator\ClosureIteratorAggregate<mixed, string>',
+    ClosureIteratorAggregate::from(
+        static function (iterable $collection): iterable {
+            foreach ($collection as $key => $item) {
+                assertType('int', $key);
+
+                yield $key => get_debug_type($item);
+            }
+        },
+        Collection::wrap([1, new \stdClass()]),
+    ),
+);