Stop event loop if exception is thrown from test (#9)

Author: trowski

src/AsyncTestCase.php

@@ -37,6 +37,15 @@ abstract class AsyncTestCase extends PHPUnitTestCase
     /** @var \Generator|null */
     private $generator;
 
+    /** @var int|null */
+    private $timeout;
+
+    final protected function runTest()
+    {
+        parent::setName('runAsyncTest');
+        return parent::runTest();
+    }
+
     /** @internal */
     final public function runAsyncTest(...$args)
     {
@@ -61,6 +70,28 @@ final public function runAsyncTest(...$args)
                 $invoked = true;
                 $exception = $error;
                 $returnValue = $value;
+
+                if ($this->timeout === null) {
+                    Loop::unreference(Loop::defer(function () use ($exception) {
+                        Loop::stop();
+
+                        if ($exception) {
+                            $this->fail(\sprintf(
+                                'An exception was thrown from the test method or promise returned from test method failed,'
+                                . ' but the event loop continued to run; set a timeout with %s::setTimeout() to allow the loop to continue'
+                                . ' to run for a given period of time; Exception thrown: %s',
+                                self::class,
+                                $exception
+                            ));
+                        }
+
+                        $this->fail(\sprintf(
+                            'The event loop continued to run after the test method completed or the promise returned resolved;'
+                            . ' set a timeout with %s::setTimeout() to allow the loop to continue to run for a given period of time',
+                            self::class
+                        ));
+                    }));
+                }
             });
         });
 
@@ -124,12 +155,6 @@ private function runAsyncTestCycle(array $args): \Generator
         return $returnValue;
     }
 
-    final protected function runTest()
-    {
-        parent::setName('runAsyncTest');
-        return parent::runTest();
-    }
-
     /**
      * Called before each test. Similar to {@see TestCase::setUp()}, except the method may return a promise or
      * coroutine (@see \Amp\call()} that will be awaited before executing the test.
@@ -169,6 +194,8 @@ final protected function setMinimumRuntime(int $runtime)
      */
     final protected function setTimeout(int $timeout)
     {
+        $this->timeout = $timeout;
+
         $this->timeoutId = Loop::delay($timeout, function () use ($timeout) {
             Loop::stop();
             Loop::setErrorHandler(null);

test/AsyncTestCaseTest.php

@@ -163,6 +163,7 @@ public function testSetMinimumRunTime(): \Generator
     public function testSetMinimumRunTimeWithWatchersOnly()
     {
         $this->setMinimumRuntime(100);
+        $this->setTimeout(200);
         Loop::delay(100, $this->createCallback(1));
     }
 
@@ -182,4 +183,21 @@ public function testCreateCallback()
 
         $this->assertSame(2, $mock(1));
     }
+
+    public function testIssue8()
+    {
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Exception thrown: ');
+
+        Loop::repeat(1000, static function () {});
+        throw new \Exception('Test exception');
+    }
+
+    public function testLoopContinuesToRunAfterResolve()
+    {
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('event loop continued to run');
+
+        Loop::repeat(1000, static function () {});
+    }
 }