Add support for routing placeholders to scoped middleware.

This allows scopes that contain routing placeholders to have middleware
attached and function. I've chosen to use the most liberal placeholder
replacement as scope variables don't allow patterns to be set.

Author: markstory

src/Routing/RouteCollection.php

@@ -425,6 +425,10 @@ public function enableMiddleware($path, array $middleware)
                 throw new RuntimeException($message);
             }
         }
+        // Matches route element pattern in Cake\Routing\Route
+        $path = '#^' . preg_quote($path, '#') . '#';
+        $path = preg_replace('/\\\\:([a-z0-9-_]+(?<![-_]))/i', '[^/]+', $path);
+
         if (!isset($this->_middlewarePaths[$path])) {
             $this->_middlewarePaths[$path] = [];
         }
@@ -447,8 +451,8 @@ public function enableMiddleware($path, array $middleware)
     public function getMatchingMiddleware($needle)
     {
         $matching = [];
-        foreach ($this->_middlewarePaths as $path => $middleware) {
-            if (strpos($needle, $path) === 0) {
+        foreach ($this->_middlewarePaths as $pattern => $middleware) {
+            if (preg_match($pattern, $needle)) {
                 $matching = array_merge($matching, $middleware);
             }
         }

tests/TestCase/Routing/RouteCollectionTest.php

@@ -747,13 +747,18 @@ public function testEnableMiddlewareWithPlaceholder()
             ->getMock();
         $this->collection->registerMiddleware('callable', $mock);
 
-        $this->collection->enableMiddleware('/articles/:article_id/comments', ['callable']);
-        $this->markTestIncomplete();
+        $this->collection->enableMiddleware('/api-:version/articles/:article_id/comments', ['callable']);
 
-        $middleware = $this->collection->getMatchingMiddleware('/articles/123/comments');
+        $middleware = $this->collection->getMatchingMiddleware('/api-1/articles/comments');
+        $this->assertEmpty($middleware);
+
+        $middleware = $this->collection->getMatchingMiddleware('/api-1/articles/yay/comments');
+        $this->assertEquals([$mock], $middleware);
+
+        $middleware = $this->collection->getMatchingMiddleware('/api-1/articles/123/comments');
         $this->assertEquals([$mock], $middleware);
 
-        $middleware = $this->collection->getMatchingMiddleware('/articles/abc-123/comments/99');
+        $middleware = $this->collection->getMatchingMiddleware('/api-abc123/articles/abc-123/comments/99');
         $this->assertEquals([$mock], $middleware);
     }