use callable typehint as php 5.6 already support it, add docblocks, a…

…nd make expectException* message call immediate call before actual method call

Signed-off-by: Abdul Malik Ikhsan <samsonasik@gmail.com>

src/PhpEnvironment/Response.php

@@ -31,7 +31,7 @@ class Response extends HttpResponse
     protected $contentSent = false;
 
     /**
-     * @var callable
+     * @var null|callable
      */
     private $headersSentHandler;
 
@@ -81,19 +81,10 @@ public function contentSent()
     }
 
     /**
-     * @param callable $handler
+     * @return void
      */
-    public function setHeadersSentHandler($handler)
+    public function setHeadersSentHandler(callable $handler)
     {
-        if (! is_callable($handler)) {
-            throw new InvalidArgumentException(
-                sprintf(
-                    'Handler must be callable with passed response object in invokable parameter, received %s',
-                    gettype($handler)
-                )
-            );
-        }
-
         $this->headersSentHandler = $handler;
     }
 

test/PhpEnvironment/ResponseTest.php

@@ -111,27 +111,16 @@ public function testSendHeadersHeadersNotAlreadySent()
         $this->assertInstanceOf(Response::class, $response->sendHeaders());
     }
 
-    public function testSendHeadersHeadersAlreadySentPassInvalidHandler()
-    {
-        $this->expectException(InvalidArgumentException::class);
-        $this->expectExceptionMessage(
-            'Handler must be callable with passed response object in invokable parameter, received string'
-        );
-
-        $response = new Response();
-        $response->setHeadersSentHandler('foo');
-        $response->sendHeaders();
-    }
-
     public function testSendHeadersHeadersAlreadySentPassValidHandler()
     {
-        $this->expectException(RuntimeException::class);
-        $this->expectExceptionMessage('Cannot send headers, headers already sent');
-
         $response = new Response();
         $response->setHeadersSentHandler(function ($response) {
             throw new RuntimeException('Cannot send headers, headers already sent');
         });
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Cannot send headers, headers already sent');
+
         $response->sendHeaders();
     }
 }