Merge pull request #45 from relayphp/fix-next-not-callable

Fix next not callable

Author: kevinsmith

src/Runner.php

@@ -14,6 +14,8 @@
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Server\MiddlewareInterface;
 use Psr\Http\Server\RequestHandlerInterface;
+use RuntimeException;
+use function is_callable;
 
 /**
  *
@@ -36,11 +38,23 @@ public function handle(ServerRequestInterface $request) : ResponseInterface
         if ($middleware instanceof MiddlewareInterface) {
             return $middleware->process($request, $this);
         }
-        
+
         if ($middleware instanceof RequestHandlerInterface) {
             return $middleware->handle($request);
         }
+        
+        if (is_callable($middleware)) {
+            return $middleware($request, $this);
+        }
 
-        return $middleware($request, $this);
+        throw new RuntimeException(
+            "Invalid middleware queue entry: {$middleware}. Middleware must either be callable or implement " .
+            MiddlewareInterface::class . '.'
+        );
+    }
+
+    public function __invoke(ServerRequestInterface $request) : ResponseInterface
+    {
+        return $this->handle($request);
     }
 }

tests/RelayTest.php

@@ -3,6 +3,9 @@
 
 use ArrayObject;
 use InvalidArgumentException;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use RuntimeException;
 use TypeError;
 use Zend\Diactoros\ServerRequestFactory;
 use Zend\Diactoros\Response;
@@ -60,7 +63,7 @@ public function testTraversableQueue()
     public function testBadQueue()
     {
         $this->expectException(TypeError::CLASS);
-        $relay = new Relay('bad');
+        new Relay('bad');
     }
 
     public function testEmptyQueue()
@@ -71,6 +74,17 @@ public function testEmptyQueue()
         new Relay([]);
     }
 
+    public function testQueueWithInvalidEntry()
+    {
+        $this->expectException(RuntimeException::CLASS);
+        $this->expectExceptionMessage(
+            "Invalid middleware queue entry: bad. Middleware must either be callable or implement Psr\Http\Server\MiddlewareInterface."
+        );
+
+        $relay = new Relay(['bad']);
+        $relay->handle(ServerRequestFactory::fromGlobals());
+    }
+
     public function testResolverEntries()
     {
         $queue = [
@@ -84,6 +98,7 @@ public function testResolverEntries()
 
         $this->assertRelay(new Relay($queue, $resolver));
     }
+
 
     public function testRequestHandlerInQueue()
     {
@@ -96,4 +111,26 @@ public function testRequestHandlerInQueue()
         $requestHandler = new Relay($queue);
         $this->assertRelay(new Relay([$requestHandler]));
     }
+    
+    public function testCallableMiddleware()
+    {
+        $queue = [
+            function (
+                ServerRequestInterface $request,
+                callable $next
+            ) : ResponseInterface {
+                $response = $next($request);
+
+                $response->getBody()->write('Hello, callable world!');
+
+                return $response;
+            },
+            $this->responder
+        ];
+
+        $relay = new Relay($queue);
+        $response = $relay->handle(ServerRequestFactory::fromGlobals());
+
+        $this->assertEquals('Hello, callable world!', (string) $response->getBody());
+    }
 }