Ensure tests run in and fiber by getting current fiber and testing it against !== null

Author: WyriHaximus

tests/RunTestsInFibersTraitTest.php

@@ -4,6 +4,7 @@
 
 namespace WyriHaximus\Tests\React\PHPUnit;
 
+use Fiber;
 use PHPUnit\Framework\TestCase;
 use React\EventLoop\Loop;
 use WyriHaximus\React\PHPUnit\RunTestsInFibersTrait;
@@ -35,6 +36,11 @@ public function allTestsAreRanInAFiber(): void
         echo 'b';
     }
 
+    public function testFiberGetCurrentReturnsAFiberInstance(): void
+    {
+        self::assertInstanceOf(Fiber::class, Fiber::getCurrent());
+    }
+
     /** @test */
     #[SomeAttribute]
     #[TimeOut(0.1)]