named constructor FrozenClock::fromUTC()

src/FrozenClock.php

@@ -4,6 +4,7 @@
 namespace Lcobucci\Clock;
 
 use DateTimeImmutable;
+use DateTimeZone;
 
 final class FrozenClock implements Clock
 {
@@ -14,6 +15,11 @@ public function __construct(DateTimeImmutable $now)
         $this->now = $now;
     }
 
+    public static function fromUTC(): FrozenClock
+    {
+        return new self(new DateTimeImmutable('now', new DateTimeZone('UTC')));
+    }
+
     public function setTo(DateTimeImmutable $now): void
     {
         $this->now = $now;

test/FrozenClockTest.php

@@ -42,4 +42,25 @@ public function nowSetChangesTheObject(): void
         self::assertNotSame($oldNow, $clock->now());
         self::assertSame($newNow, $clock->now());
     }
+
+    /**
+     * @test
+     *
+     * @covers \Lcobucci\Clock\FrozenClock::fromUTC
+     *
+     * @uses \Lcobucci\Clock\FrozenClock::__construct
+     * @uses \Lcobucci\Clock\FrozenClock::now
+     */
+    public function fromUTCCreatesClockFrozenAtCurrentSystemTimeInUTC(): void
+    {
+        $lower = new DateTimeImmutable();
+        $clock = FrozenClock::fromUTC();
+        $upper = new DateTimeImmutable();
+
+        $now = $clock->now();
+
+        self::assertGreaterThanOrEqual($lower->getTimestamp(), $now->getTimestamp());
+        self::assertLessThanOrEqual($upper->getTimestamp(), $now->getTimestamp());
+        self::assertEquals('UTC', $now->getTimezone()->getName());
+    }
 }