Add mask processor and tests

src/Parser.php

@@ -125,6 +125,37 @@ public function get($key = null, $default = null)
         return $default;
     }
 
+    /**
+     * Mask input data with a given mapping.
+     *
+     * @param array $mask
+     *
+     * @return array
+     */
+    public function mask(array $mask)
+    {
+        $keys = array();
+        foreach ($mask as $key => $value) {
+            $keys[] = $key . (is_array($value) ? $this->process_mask($value) : '');
+        }
+
+        return $this->only($keys);
+    }
+
+    /**
+     * Recursive processor for processing user masks.
+     *
+     * @param array $mask
+     *
+     * @return string
+     */
+    private function process_mask($mask)
+    {
+        foreach ($mask as $key => $value) {
+            return '.' . $key . (is_array($value) ? $this->process_item($value) : '');
+        }
+    }
+
     /**
      * Parse the HTTP payload data, autodetect format and return all data in array.
      *  Override the format by providing a content type.

tests/ParserTest.php

@@ -15,6 +15,21 @@ protected function tearDown()
         m::close();
     }
 
+    /** @test */
+    public function mask_payload()
+    {
+        $parser = m::mock('Nathanmac\Utilities\Parser\Parser')
+            ->shouldDeferMissing()
+            ->shouldAllowMockingProtectedMethods();
+
+        $parser->shouldReceive('getPayload')
+            ->andReturn('{"message": {"title": "Hello World", "body": "Some message content"}, "comments": [{ "title": "hello", "message": "hello world"}, {"title": "world", "message": "hello world"}]}');
+
+        $this->assertEquals(array("message" => array("title" => "Hello World")), $parser->mask(array('message' => array('title' => '*'))));
+        $this->assertEquals(array("comments" => array(array("title" => "hello", "message" => "hello world"), array("title" => "world", "message" => "hello world"))), $parser->mask(array('comments' => '*')));
+        $this->assertEquals(array('posts' => null), $parser->mask(array('posts' => '*')));
+    }
+
     /** @test */
     public function wildcards_with_simple_structure_json()
     {