Error report improvement

src/Exception/InvalidMiddlewareException.php

@@ -0,0 +1,31 @@
+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @see       http://github.com/zendframework/zend-stratigility for the canonical source repository
+ * @copyright Copyright (c) 2015 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   https://github.com/zendframework/zend-stratigility/blob/master/LICENSE.md New BSD License
+ */
+
+namespace Zend\Stratigility\Exception;
+
+use InvalidArgumentException;
+
+class InvalidMiddlewareException extends InvalidArgumentException
+{
+    public static function fromValue($value)
+    {
+        $received = gettype($value);
+
+        if (is_object($value)) {
+            $received = get_class($value);
+        }
+
+        return new self(
+            sprintf(
+                'Middleware must be callable, %s found',
+                $received
+            )
+        );
+    }
+}

src/MiddlewarePipe.php

@@ -9,7 +9,7 @@
 
 namespace Zend\Stratigility;
 
-use InvalidArgumentException;
+use Zend\Stratigility\Exception\InvalidMiddlewareException;
 use Psr\Http\Message\ServerRequestInterface as Request;
 use Psr\Http\Message\ResponseInterface as Response;
 use SplQueue;
@@ -108,7 +108,7 @@ public function pipe($path, $middleware = null)
 
         // Ensure we have a valid handler
         if (! is_callable($middleware)) {
-            throw new InvalidArgumentException('Middleware must be callable');
+            throw InvalidMiddlewareException::fromValue($middleware);
         }
 
         $this->pipeline->enqueue(new Route(