Replaced call_user_func* with native calls (#165)

Author: GrahamCampbell

src/EachPromise.php

@@ -135,7 +135,7 @@ private function refillPending(): void
 
         // Add only up to N pending promises.
         $concurrency = is_callable($this->concurrency)
-            ? call_user_func($this->concurrency, count($this->pending))
+            ? ($this->concurrency)(count($this->pending))
             : $this->concurrency;
         $concurrency = max($concurrency - count($this->pending), 0);
         // Concurrency may be set to 0 to disallow new promises.
@@ -170,8 +170,7 @@ private function addPending(): bool
         $this->pending[$idx] = $promise->then(
             function ($value) use ($idx, $key): void {
                 if ($this->onFulfilled) {
-                    call_user_func(
-                        $this->onFulfilled,
+                    ($this->onFulfilled)(
                         $value,
                         $key,
                         $this->aggregate
@@ -181,8 +180,7 @@ function ($value) use ($idx, $key): void {
             },
             function ($reason) use ($idx, $key): void {
                 if ($this->onRejected) {
-                    call_user_func(
-                        $this->onRejected,
+                    ($this->onRejected)(
                         $reason,
                         $key,
                         $this->aggregate

tests/CoroutineTest.php

@@ -29,13 +29,13 @@ public function testShouldProxyPromiseMethodsToResultPromise($method, $args = []
     {
         $coroutine = new Coroutine(function () { yield 0; });
         $mockPromise = $this->getMockForAbstractClass(PromiseInterface::class);
-        call_user_func_array([$mockPromise->expects($this->once())->method($method), 'with'], $args);
+        $mockPromise->expects($this->once())->method($method)->with(...$args);
 
         $resultPromiseProp = (new ReflectionClass(Coroutine::class))->getProperty('result');
         $resultPromiseProp->setAccessible(true);
         $resultPromiseProp->setValue($coroutine, $mockPromise);
 
-        call_user_func_array([$coroutine, $method], $args);
+        $coroutine->{$method}(...$args);
     }
 
     public function promiseInterfaceMethodProvider()