Merge pull request #95 from patchlevel/add-clock

add clock

src/Clock.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing;
+
+use DateTimeImmutable;
+
+use function sleep;
+use function sprintf;
+
+final class Clock
+{
+    private static ?DateTimeImmutable $frozenDateTime = null;
+
+    public static function freeze(DateTimeImmutable $frozenDateTime): void
+    {
+        self::$frozenDateTime = $frozenDateTime;
+    }
+
+    /**
+     * @param positive-int $seconds
+     */
+    public static function sleep(int $seconds): void
+    {
+        if (self::$frozenDateTime instanceof DateTimeImmutable) {
+            self::$frozenDateTime = self::$frozenDateTime->modify(sprintf('+%s seconds', $seconds));
+
+            return;
+        }
+
+        sleep($seconds);
+    }
+
+    public static function createDateTimeImmutable(): DateTimeImmutable
+    {
+        return self::$frozenDateTime ?: new DateTimeImmutable();
+    }
+
+    public static function reset(): void
+    {
+        self::$frozenDateTime = null;
+    }
+}

tests/Unit/ClockTest.php

@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Tests\Unit;
+
+use DateTimeImmutable;
+use Patchlevel\EventSourcing\Clock;
+use PHPUnit\Framework\TestCase;
+
+class ClockTest extends TestCase
+{
+    protected function setUp(): void
+    {
+        Clock::reset();
+    }
+
+    protected function tearDown(): void
+    {
+        Clock::reset();
+    }
+
+    public function testCreateDateTimeImmutable(): void
+    {
+        $before = new DateTimeImmutable();
+        $date = Clock::createDateTimeImmutable();
+        $after = new DateTimeImmutable();
+
+        self::assertGreaterThanOrEqual($before, $date);
+        self::assertLessThanOrEqual($after, $date);
+    }
+
+    public function testCreateDateTimeImmutableWithFrozenClock(): void
+    {
+        $current = new DateTimeImmutable();
+
+        Clock::freeze($current);
+
+        $new = Clock::createDateTimeImmutable();
+
+        self::assertEquals($current, $new);
+    }
+
+    public function testReset(): void
+    {
+        $current = new DateTimeImmutable();
+        Clock::freeze($current);
+        Clock::reset();
+
+        $before = new DateTimeImmutable();
+        $date = Clock::createDateTimeImmutable();
+        $after = new DateTimeImmutable();
+
+        self::assertNotEquals($current, $date);
+        self::assertGreaterThanOrEqual($before, $date);
+        self::assertLessThanOrEqual($after, $date);
+    }
+
+    public function testSleep(): void
+    {
+        $date1 = Clock::createDateTimeImmutable();
+        Clock::sleep(1);
+        $date2 = Clock::createDateTimeImmutable();
+
+        $diff = $date1->diff($date2);
+
+        self::assertEquals(1, $diff->s);
+    }
+
+    public function testSleepWithFrozenClock(): void
+    {
+        $current = new DateTimeImmutable();
+        Clock::freeze($current);
+
+        $date1 = Clock::createDateTimeImmutable();
+        Clock::sleep(45);
+        $date2 = Clock::createDateTimeImmutable();
+
+        $diff = $date1->diff($date2);
+
+        self::assertEquals(45, $diff->s);
+    }
+}