Add Fiber-based async() function

clue · WyriHaximus · commit b933e251a84c · 2021-11-21T17:46:32.000+01:00
diff --git a/src/functions.php b/src/functions.php
@@ -10,6 +10,29 @@
 use function React\Promise\reject;
 use function React\Promise\resolve;
 
+/**
+ *
+ * @template T
+ * @param callable(...$args):T $coroutine
+ * @param mixed ...$args
+ * @return PromiseInterface<T>
+ */
+function async(callable $coroutine, ...$args): PromiseInterface
+{
+    return new Promise(function (callable $resolve, callable $reject) use ($coroutine, $args): void {
+        $fiber = new \Fiber(function () use ($resolve, $reject, $coroutine, $args): void {
+            try {
+                $resolve($coroutine(...$args));
+            } catch (\Throwable $exception) {
+                $reject($exception);
+            }
+        });
+
+        Loop::futureTick(static fn() => $fiber->start());
+    });
+}
+
+
 /**
  * Block waiting for the given `$promise` to be fulfilled.
  *
diff --git a/tests/AwaitTest.php b/tests/AwaitTest.php
@@ -8,18 +8,24 @@
 
 class AwaitTest extends TestCase
 {
-    public function testAwaitThrowsExceptionWhenPromiseIsRejectedWithException()
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitThrowsExceptionWhenPromiseIsRejectedWithException(callable $await)
     {
         $promise = new Promise(function () {
             throw new \Exception('test');
         });
 
         $this->expectException(\Exception::class);
         $this->expectExceptionMessage('test');
-        React\Async\await($promise);
+        $await($promise);
     }
 
-    public function testAwaitThrowsUnexpectedValueExceptionWhenPromiseIsRejectedWithFalse()
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitThrowsUnexpectedValueExceptionWhenPromiseIsRejectedWithFalse(callable $await)
     {
         if (!interface_exists('React\Promise\CancellablePromiseInterface')) {
             $this->markTestSkipped('Promises must be rejected with a \Throwable instance since Promise v3');
@@ -31,10 +37,13 @@ public function testAwaitThrowsUnexpectedValueExceptionWhenPromiseIsRejectedWith
 
         $this->expectException(\UnexpectedValueException::class);
         $this->expectExceptionMessage('Promise rejected with unexpected value of type bool');
-        React\Async\await($promise);
+        $await($promise);
     }
 
-    public function testAwaitThrowsUnexpectedValueExceptionWhenPromiseIsRejectedWithNull()
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitThrowsUnexpectedValueExceptionWhenPromiseIsRejectedWithNull(callable $await)
     {
         if (!interface_exists('React\Promise\CancellablePromiseInterface')) {
             $this->markTestSkipped('Promises must be rejected with a \Throwable instance since Promise v3');
@@ -46,10 +55,13 @@ public function testAwaitThrowsUnexpectedValueExceptionWhenPromiseIsRejectedWith
 
         $this->expectException(\UnexpectedValueException::class);
         $this->expectExceptionMessage('Promise rejected with unexpected value of type NULL');
-        React\Async\await($promise);
+        $await($promise);
     }
 
-    public function testAwaitThrowsErrorWhenPromiseIsRejectedWithError()
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitThrowsErrorWhenPromiseIsRejectedWithError(callable $await)
     {
         $promise = new Promise(function ($_, $reject) {
             throw new \Error('Test', 42);
@@ -58,19 +70,25 @@ public function testAwaitThrowsErrorWhenPromiseIsRejectedWithError()
         $this->expectException(\Error::class);
         $this->expectExceptionMessage('Test');
         $this->expectExceptionCode(42);
-        React\Async\await($promise);
+        $await($promise);
     }
 
-    public function testAwaitReturnsValueWhenPromiseIsFullfilled()
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitReturnsValueWhenPromiseIsFullfilled(callable $await)
     {
         $promise = new Promise(function ($resolve) {
             $resolve(42);
         });
 
-        $this->assertEquals(42, React\Async\await($promise));
+        $this->assertEquals(42, $await($promise));
     }
 
-    public function testAwaitReturnsValueWhenPromiseIsFulfilledEvenWhenOtherTimerStopsLoop()
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitReturnsValueWhenPromiseIsFulfilledEvenWhenOtherTimerStopsLoop(callable $await)
     {
         $this->markTestIncomplete();
 
@@ -83,10 +101,13 @@ public function testAwaitReturnsValueWhenPromiseIsFulfilledEvenWhenOtherTimerSto
             Loop::stop();
         });
 
-        $this->assertEquals(2, React\Async\await($promise));
+        $this->assertEquals(2, $await($promise));
     }
 
-    public function testAwaitShouldNotCreateAnyGarbageReferencesForResolvedPromise()
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitShouldNotCreateAnyGarbageReferencesForResolvedPromise(callable $await)
     {
         if (class_exists('React\Promise\When')) {
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
@@ -97,13 +118,16 @@ public function testAwaitShouldNotCreateAnyGarbageReferencesForResolvedPromise()
         $promise = new Promise(function ($resolve) {
             $resolve(42);
         });
-        React\Async\await($promise);
+        $await($promise);
         unset($promise);
 
         $this->assertEquals(0, gc_collect_cycles());
     }
 
-    public function testAwaitShouldNotCreateAnyGarbageReferencesForRejectedPromise()
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitShouldNotCreateAnyGarbageReferencesForRejectedPromise(callable $await)
     {
         if (class_exists('React\Promise\When')) {
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
@@ -115,7 +139,7 @@ public function testAwaitShouldNotCreateAnyGarbageReferencesForRejectedPromise()
             throw new \RuntimeException();
         });
         try {
-            React\Async\await($promise);
+            $await($promise);
         } catch (\Exception $e) {
             // no-op
         }
@@ -124,7 +148,10 @@ public function testAwaitShouldNotCreateAnyGarbageReferencesForRejectedPromise()
         $this->assertEquals(0, gc_collect_cycles());
     }
 
-    public function testAwaitShouldNotCreateAnyGarbageReferencesForPromiseRejectedWithNullValue()
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitShouldNotCreateAnyGarbageReferencesForPromiseRejectedWithNullValue(callable $await)
     {
         if (!interface_exists('React\Promise\CancellablePromiseInterface')) {
             $this->markTestSkipped('Promises must be rejected with a \Throwable instance since Promise v3');
@@ -140,12 +167,18 @@ public function testAwaitShouldNotCreateAnyGarbageReferencesForPromiseRejectedWi
             $reject(null);
         });
         try {
-            React\Async\await($promise);
+            $await($promise);
         } catch (\Exception $e) {
             // no-op
         }
         unset($promise, $e);
 
         $this->assertEquals(0, gc_collect_cycles());
     }
+
+    public function provideAwaiters(): iterable
+    {
+        yield 'await' => [static fn (React\Promise\PromiseInterface $promise): mixed => React\Async\await($promise)];
+        yield 'async' => [static fn (React\Promise\PromiseInterface $promise): mixed => React\Async\await(React\Async\async(static fn(): mixed => $promise))];
+    }
 }
