added isDisallowed Method and Tests

Author: waknauss

src/Robot/RobotsTxt.php

@@ -53,4 +53,20 @@ public function isAllowed($userAgent, $path)
         $urlParts = array_filter(explode('/', $path));
         return $this->tree->allowed(strtolower($userAgent), $urlParts) !== false;
     }
+
+    /**
+     * Is the given user agent disallowed access to the given resource?
+     * @param  string  $userAgent The user agent to check
+     * @param  string  $path The path of the url
+     * @return bool|null
+     */
+    public function isDisallowed($userAgent, $path) 
+    {
+        $status = $this->isAllowed($userAgent, $path);
+        if ($status===true) {
+            return false;
+        }
+
+        return true;
+    }
 }

tests/RobotTest.php

@@ -28,6 +28,22 @@ public function testBasicDisallow()
         $this->assertFalse(self::getRobotsTxt('google')->isAllowed('robot', '/print'), 'robot cannot access /print');
     }
 
+    /**
+     * Test that we are not allowed to access a resource which is forbidden using the isDisallowed method
+     */
+    public function testBasicDisallow_Disallowed_method()
+    {
+        $this->assertTrue(self::getRobotsTxt('google')->isDisallowed('robot','/search'),'robot should not access /search');
+    }
+
+    /**
+     * Test that we are allowed to access a given resource using the isDisallowed method
+     */
+    public function testBasicIsDisallowed_returning_false() 
+    {
+        $this->assertFalse(self::getRobotsTxt('google')->isDisallowed('robot','/m/finance'),'robot should be able to access /m/finance');
+    }
+
     /**
      * Test we are allowed to access a resource with Allow:
      */