Added DateTime:comesBefore, added tests for DateTime

src/Surfnet/Stepup/DateTime/DateTime.php

@@ -78,17 +78,26 @@ public function __construct(CoreDateTime $dateTime = null)
     }
 
     /**
-     * @param DateInterval $intervalSpec
+     * @param DateInterval $interval
      * @return DateTime
      */
-    public function add(DateInterval $intervalSpec)
+    public function add(DateInterval $interval)
     {
         $dateTime = clone $this->dateTime;
-        $dateTime->add($intervalSpec);
+        $dateTime->add($interval);
 
         return new self($dateTime);
     }
 
+    /**
+     * @param DateTime $dateTime
+     * @return boolean
+     */
+    public function comesBefore(DateTime $dateTime)
+    {
+        return $this->dateTime < $dateTime->dateTime;
+    }
+
     /**
      * @param DateTime $dateTime
      * @return boolean

src/Surfnet/Stepup/Tests/DateTime/DateTimeTest.php

@@ -0,0 +1,103 @@
+<?php
+
+namespace Surfnet\Stepup\Tests\DateTime;
+
+use DateInterval;
+use DateTime as CoreDateTime;
+use PHPUnit_Framework_TestCase as UnitTest;
+use Surfnet\Stepup\DateTime\DateTime;
+
+class DateTimeTest extends UnitTest
+{
+    /**
+     * Might seem a bit overdone, but we rely on this specific format in quite a bit of places. If the format changes
+     * this might lead to some unforeseen errors. This ensures that if the format is changed, this test fails and
+     * that you're hopefully reading this as an instruction to check all the places that handle datetime for
+     * compatibility with the new format. Think about log(-processors), (de-)serializers, etc.
+     *
+     * @test
+     * @group domain
+     */
+    public function the_configured_format_is_what_is_needed_for_correct_application_behavior()
+    {
+        $this->assertEquals('Y-m-d\\TH:i:sP', DateTime::FORMAT);
+    }
+
+    /**
+     * Ensure that the __toString of our DateTime object actually uses the correct format. For the reason why, read the
+     * docblock above the {@see the_configured_format_is_what_is_needed_for_correct_application_behavior()} test
+     *
+     * @test
+     * @group domain
+     */
+    public function to_string_returns_the_time_in_the_correct_format()
+    {
+        $coreDateTimeObject = new CoreDateTime('@1000');
+        $ourDateTimeObject  = new DateTime(new CoreDateTime('@1000'));
+
+        $this->assertEquals($coreDateTimeObject->format(DateTime::FORMAT), (string) $ourDateTimeObject);
+    }
+
+    /**
+     * @test
+     * @group domain
+     */
+    public function add_returns_a_different_object_that_has_the_interval_added()
+    {
+        $base     = new DateTime(new CoreDateTime('@1000'));
+        $interval = new DateInterval('PT1S');
+
+        $result = $base->add($interval);
+
+        $this->assertFalse($result === $base, 'DateTime::add must return a different object');
+        $this->assertTrue($result > $base, 'DateTime::add adds the interval to the new object');
+    }
+
+    /**
+     * @test
+     * @group domain
+     */
+    public function comes_before_works_with_exclusive_comparison()
+    {
+        $base   = new DateTime(new CoreDateTime('@1000'));
+        $before = new DateTime(new CoreDateTime('@999'));
+        $same   = new DateTime(new CoreDateTime('@1000'));
+        $after  = new DateTime(new CoreDateTime('@1001'));
+
+        $this->assertTrue($before->comesBefore($base));
+        $this->assertFalse($same->comesBefore($base));
+        $this->assertFalse($after->comesBefore($base));
+    }
+
+    /**
+     * @test
+     * @group domain
+     */
+    public function comes_after_works_with_exclusive_comparison()
+    {
+        $base   = new DateTime(new CoreDateTime('@1000'));
+        $before = new DateTime(new CoreDateTime('@999'));
+        $same   = new DateTime(new CoreDateTime('@1000'));
+        $after  = new DateTime(new CoreDateTime('@1001'));
+
+        $this->assertFalse($before->comesAfter($base));
+        $this->assertFalse($same->comesAfter($base));
+        $this->assertTrue($after->comesAfter($base));
+    }
+
+    /**
+     * @test
+     * @group domain
+     */
+    public function comes_after_or_is_equal_works_with_inclusive_comparison()
+    {
+        $base   = new DateTime(new CoreDateTime('@1000'));
+        $before = new DateTime(new CoreDateTime('@999'));
+        $same   = new DateTime(new CoreDateTime('@1000'));
+        $after  = new DateTime(new CoreDateTime('@1001'));
+
+        $this->assertFalse($before->comesAfterOrIsEqual($base));
+        $this->assertTrue($same->comesAfterOrIsEqual($base));
+        $this->assertTrue($after->comesAfterOrIsEqual($base));
+    }
+}