Improve await() in main to avoid unneeded futureTick() calls

Author: clue

src/SimpleFiber.php

@@ -20,7 +20,11 @@ public function __construct()
     public function resume(mixed $value): void
     {
         if ($this->fiber === null) {
-            Loop::futureTick(static fn() => \Fiber::suspend(static fn() => $value));
+            if (\Fiber::getCurrent() !== self::$scheduler) {
+                Loop::futureTick(static fn() => \Fiber::suspend(static fn() => $value));
+            } else {
+                \Fiber::suspend(static fn() => $value);
+            }
             return;
         }
 
@@ -30,7 +34,11 @@ public function resume(mixed $value): void
     public function throw(\Throwable $throwable): void
     {
         if ($this->fiber === null) {
-            Loop::futureTick(static fn() => \Fiber::suspend(static fn() => throw $throwable));
+            if (\Fiber::getCurrent() !== self::$scheduler) {
+                Loop::futureTick(static fn() => \Fiber::suspend(static fn() => throw $throwable));
+            } else {
+                \Fiber::suspend(static fn() => throw $throwable);
+            }
             return;
         }
 

tests/AsyncTest.php

@@ -143,6 +143,22 @@ public function testAsyncReturnsPromiseThatFulfillsWithValueWhenCallbackReturnsA
         $this->assertEquals(42, $value);
     }
 
+    public function testAsyncReturnsPromiseThatRejectsWithExceptionWhenCallbackThrowsAfterAwaitingPromise()
+    {
+        $promise = async(function () {
+            $promise = new Promise(function ($_, $reject) {
+                Loop::addTimer(0.001, fn () => $reject(new \RuntimeException('Foo', 42)));
+            });
+
+            return await($promise);
+        })();
+
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Foo');
+        $this->expectExceptionCode(42);
+        await($promise);
+    }
+
     public function testAsyncReturnsPromiseThatFulfillsWithValueWhenCallbackReturnsAfterAwaitingTwoConcurrentPromises()
     {
         $promise1 = async(function () {

tests/AwaitTest.php

@@ -4,6 +4,7 @@
 
 use React;
 use React\EventLoop\Loop;
+use React\Promise\Deferred;
 use React\Promise\Promise;
 
 class AwaitTest extends TestCase
@@ -43,6 +44,30 @@ public function testAwaitThrowsExceptionWithoutRunningLoop(callable $await)
         }
     }
 
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitThrowsExceptionImmediatelyWhenPromiseIsRejected(callable $await)
+    {
+        $deferred = new Deferred();
+
+        $ticks = 0;
+        Loop::futureTick(function () use (&$ticks) {
+            ++$ticks;
+            Loop::futureTick(function () use (&$ticks) {
+                ++$ticks;
+            });
+        });
+
+        Loop::futureTick(fn() => $deferred->reject(new \RuntimeException()));
+
+        try {
+            $await($deferred->promise());
+        } catch (\RuntimeException $e) {
+            $this->assertEquals(1, $ticks);
+        }
+    }
+
     /**
      * @dataProvider provideAwaiters
      */
@@ -130,6 +155,27 @@ public function testAwaitReturnsValueImmediatelyWithoutRunningLoop(callable $awa
         $this->assertTrue($now);
     }
 
+    /**
+     * @dataProvider provideAwaiters
+     */
+    public function testAwaitReturnsValueImmediatelyWhenPromiseIsFulfilled(callable $await)
+    {
+        $deferred = new Deferred();
+
+        $ticks = 0;
+        Loop::futureTick(function () use (&$ticks) {
+            ++$ticks;
+            Loop::futureTick(function () use (&$ticks) {
+                ++$ticks;
+            });
+        });
+
+        Loop::futureTick(fn() => $deferred->resolve(42));
+
+        $this->assertEquals(42, $await($deferred->promise()));
+        $this->assertEquals(1, $ticks);
+    }
+
     /**
      * @dataProvider provideAwaiters
      */