feat: add some typing for static analysis

src/Adapter/Tornado/EventLoop.php

@@ -237,6 +237,8 @@ public function delay(int $milliseconds): Promise
             while (microtime(true) < $endTime) {
                 yield $this->idle();
             }
+
+            return null;
         })());
     }
 

src/EventLoop.php

@@ -8,13 +8,23 @@ interface EventLoop
      * Waits the resolution of a promise, and returns its value.
      * You should use this function once for your global result.
      *
-     * @return mixed
+     * @template T
+     *
+     * @param Promise<T> $promise
+     *
+     * @return T
      */
     public function wait(Promise $promise);
 
     /**
      * Registers a generator in the event loop to execute it asynchronously.
      * The returned promise will be resolved with the value returned by the generator.
+     *
+     * @template T
+     *
+     * @param \Generator<int, Promise, mixed, T> $generator
+     *
+     * @return Promise<T>
      */
     public function async(\Generator $generator): Promise;
 
@@ -28,8 +38,11 @@ public function promiseAll(Promise ...$promises): Promise;
      * $function applied to each elements of input traversable.
      * You should use this function each time that you use yield in a foreach loop.
      *
-     * @param \Traversable|array $traversable Input elements
-     * @param callable           $function    must return a generator from an input value, and an optional key
+     * @template TKey of array-key
+     * @template TValue
+     *
+     * @param \Traversable<TKey, TValue>|array<TKey, TValue>                 $traversable Input elements
+     * @param callable(TValue, TKey): \Generator<int, Promise, mixed, mixed> $function
      */
     public function promiseForeach($traversable, callable $function): Promise;
 
@@ -41,7 +54,11 @@ public function promiseRace(Promise ...$promises): Promise;
     /**
      * Creates a promise already resolved with $value.
      *
-     * @param mixed $value
+     * @template T
+     *
+     * @param T $value
+     *
+     * @return Promise<T>
      */
     public function promiseFulfilled($value): Promise;
 
@@ -52,13 +69,17 @@ public function promiseRejected(\Throwable $throwable): Promise;
 
     /**
      * Creates a promise that will be resolved to null in a future tick of the event loop.
+     *
+     * @return Promise<null>
      */
     public function idle(): Promise;
 
     /**
      * Creates a promise that will be resolved to null after a fixed time.
      * ⚠️ The actual measured delay can be greater if your event loop is busy!
      * It also can be a little smaller, depending on your event loop (or system clock) accuracy.
+     *
+     * @return Promise<null>
      */
     public function delay(int $milliseconds): Promise;
 
@@ -72,6 +93,8 @@ public function deferred(): Deferred;
      * ⚠️ Error handling (stream connection closed for example) might differ between implementations.
      *
      * @param resource $stream
+     *
+     * @return Promise<resource>
      */
     public function readable($stream): Promise;
 
@@ -80,6 +103,8 @@ public function readable($stream): Promise;
      * ⚠️ Error handling (stream connection closed for example) might differ between implementations.
      *
      * @param resource $stream
+     *
+     * @return Promise<resource>
      */
     public function writable($stream): Promise;
 }

src/HttpClient.php

@@ -3,12 +3,15 @@
 namespace M6Web\Tornado;
 
 use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ResponseInterface;
 
 interface HttpClient
 {
     /**
      * Sends a http request and returns a promise that will be resolved with a
      * Psr\Http\Message\ResponseInterface
+     *
+     * @return Promise<ResponseInterface>
      */
     public function sendRequest(RequestInterface $request): Promise;
 }

src/Promise.php

@@ -4,6 +4,9 @@
 
 /**
  * To resolve the value of a promise, you have to yield it from a generator registered in the event loop.
+ *
+ * @template-covariant TValue
+ * @psalm-yield TValue
  */
 interface Promise
 {

tests/Adapter/Guzzle/GuzzleMockWrapper.php

@@ -10,9 +10,6 @@ final class GuzzleMockWrapper implements GuzzleClientWrapper
     /** @var \GuzzleHttp\Client */
     private $guzzleClient;
 
-    /** @var array */
-    private $transactions = [];
-
     /** @var int */
     public $ticks;
 

tests/EventLoopTest/AsyncTest.php

@@ -49,6 +49,7 @@ public function testYieldingInvalidValueMayThrowAnError(): void
         };
 
         $eventLoop = $this->createEventLoop();
+        /** @phpstan-ignore-next-line phpstan detects the generator yields a non-promise */
         $promise = $eventLoop->async($createGenerator());
 
         $this->expectException(\Error::class);
@@ -245,6 +246,8 @@ public function testEventLoopShouldNotThrowInCaseOfExplicitlyRejectedPromise():
         $generatorWaitALittle = function () use ($eventLoop) {
             yield $eventLoop->idle();
             yield $eventLoop->idle();
+
+            return null;
         };
 
         $unwatchedRejectedPromise = $eventLoop->promiseRejected(new \Exception('Rejected Promise'));

tests/EventLoopTest/PromiseForeachTest.php

@@ -46,6 +46,7 @@ public function testPromiseForeachShouldThrowIfCallbackDoesNotReturnGenerator():
 
         $this->expectException(\TypeError::class);
         $eventLoop->wait(
+            /* @phpstan-ignore-next-line phpstan detects the callback is invalid */
             $eventLoop->promiseForeach([1], $callback)
         );
     }