Adds support for http-interop middleware

Middleware injected into a Route instance may be
http-interop/http-middleware compatible. Previously, only callables and
service names were allowed, but now it supports the interop interface.

composer.json

@@ -19,7 +19,8 @@
     "require": {
         "php": "^5.6 || ^7.0",
         "psr/http-message": "^1.0",
-        "fig/http-message-util": "^1.1"
+        "fig/http-message-util": "^1.1",
+        "http-interop/http-middleware": "^0.4.1"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.7 || ^5.6",

src/Route.php

@@ -8,6 +8,7 @@
 namespace Zend\Expressive\Router;
 
 use Fig\Http\Message\RequestMethodInterface as RequestMethod;
+use Interop\Http\ServerMiddleware\MiddlewareInterface;
 
 /**
  * Value object representing a single route.
@@ -68,7 +69,7 @@ class Route
 
     /**
      * @param string $path Path to match.
-     * @param string|callable $middleware Middleware to use when this route is matched.
+     * @param string|callable|MiddlewareInterface $middleware Middleware to use when this route is matched.
      * @param int|array Allowed HTTP methods; defaults to HTTP_METHOD_ANY.
      * @param string|null $name the route name
      * @throws Exception\InvalidArgumentException for invalid path type.
@@ -81,8 +82,14 @@ public function __construct($path, $middleware, $methods = self::HTTP_METHOD_ANY
             throw new Exception\InvalidArgumentException('Invalid path; must be a string');
         }
 
-        if (! is_callable($middleware) && ! is_string($middleware) && ! is_array($middleware)) {
-            throw new Exception\InvalidArgumentException('Invalid middleware; must be callable or a service name');
+        if (! is_callable($middleware)
+            && ! $middleware instanceof MiddlewareInterface
+            && ! is_string($middleware)
+        ) {
+            throw new Exception\InvalidArgumentException(sprintf(
+                'Invalid middleware; must be a callable, a %s instance, or a service name',
+                MiddlewareInterface::class
+            ));
         }
 
         if ($methods !== self::HTTP_METHOD_ANY && ! is_array($methods)) {
@@ -136,7 +143,7 @@ public function getName()
     }
 
     /**
-     * @return string|callable|array
+     * @return string|callable|MiddlewareInterface
      */
     public function getMiddleware()
     {

test/RouteTest.php

@@ -8,6 +8,7 @@
 namespace ZendTest\Expressive\Router;
 
 use Fig\Http\Message\RequestMethodInterface as RequestMethod;
+use Interop\Http\ServerMiddleware\MiddlewareInterface;
 use PHPUnit_Framework_TestCase as TestCase;
 use Zend\Expressive\Router\Exception\InvalidArgumentException;
 use Zend\Expressive\Router\Route;
@@ -128,11 +129,7 @@ public function testThrowsExceptionDuringConstructionIfPathIsNotString()
 
     public function testThrowsExceptionDuringConstructionOnInvalidMiddleware()
     {
-        $this->setExpectedException(
-            InvalidArgumentException::class,
-            'Invalid middleware; must be callable or a service name'
-        );
-
+        $this->setExpectedException(InvalidArgumentException::class, 'Invalid middleware');
         new Route('/foo', 12345);
     }
 
@@ -208,4 +205,36 @@ public function testPassingWildcardMethodDoesNotMarkAsImplicit()
         $this->assertFalse($route->implicitHead());
         $this->assertFalse($route->implicitOptions());
     }
+
+    public function testAllowsHttpInteropMiddleware()
+    {
+        $middleware = $this->prophesize(MiddlewareInterface::class)->reveal();
+        $route = new Route('/test', $middleware, Route::HTTP_METHOD_ANY);
+        $this->assertSame($middleware, $route->getMiddleware());
+    }
+
+    public function invalidMiddleware()
+    {
+        // Strings are allowed, because they could be service names.
+        // Non-callable arrays are not allowed.
+        return [
+            'null'                => [null],
+            'true'                => [true],
+            'false'               => [false],
+            'zero'                => [0],
+            'int'                 => [1],
+            'int'                 => [1],
+            'non-callable-array'  => [['foo', 'bar']],
+            'non-callable-object' => [(object) ['handler' => 'foo']],
+        ];
+    }
+
+    /**
+     * @dataProvider invalidMiddleware
+     */
+    public function testConstructorRaisesExceptionForInvalidMiddleware($middleware)
+    {
+        $this->setExpectedException(InvalidArgumentException::class, 'Invalid middleware');
+        new Route('/test', $middleware);
+    }
 }