From b9ccca9728bd18cad818ec8abc78d5f052de9492 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Albert=20Cansado=20Sola=CC=80?= <albert.cansado@gmail.com>
Date: Thu, 22 Aug 2019 13:16:36 +0200
Subject: [PATCH 1/2] whitelist feature

---
 src/Filter.php       | 65 +++++++++++++++++++++++++++++++++++++++++++-
 tests/FilterTest.php | 57 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 121 insertions(+), 1 deletion(-)

diff --git a/src/Filter.php b/src/Filter.php
index 9fd9c35..77c3ad7 100644
--- a/src/Filter.php
+++ b/src/Filter.php
@@ -37,6 +37,8 @@ class Filter
      */
     protected $globalChain = null;
 
+    protected $whiteList = [];
+
     /**
      * Set a filter for a value on a specific key
      *
@@ -109,7 +111,9 @@ public function addFilterRule(FilterRule $rule, $key = null)
      */
     public function filter(array $data)
     {
-        $data = $this->filterArrayWithGlobalChain($data);
+        $data = $this->filterArrayWithGlobalChain(
+            $this->applyWhiteList($data)
+        );
 
         $this->data = new Container($data);
 
@@ -118,6 +122,65 @@ public function filter(array $data)
         return $this->data->getArrayCopy();
     }
 
+    /**
+     * Set a list of keys to be returned in the end
+     *
+     * @param array $keys
+     * @return void
+     */
+    public function whiteList(array $keys)
+    {
+        $this->whiteList = $keys;
+    }
+
+    /**
+     * Purge initial fields using white list
+     *
+     * @param array $data
+     * @return array
+     */
+    protected function applyWhiteList(array $data)
+    {
+        if (empty($this->whiteList)) {
+            return $data;
+        }
+
+        $allowed = [];
+        foreach ($this->whiteList as $key) {
+            if (strpos($key, '.') !== false) {
+                $allowed = $this->deepWhitelist($key, $allowed, $data);
+            } else {
+                $allowed[$key] = $data[$key];
+            }
+        }
+
+        return $allowed;
+    }
+
+    /**
+     * Uses dot-notation to purge initial data
+     *
+     * @param string $key
+     * @param array $result
+     * @param array $data
+     * @return array
+     */
+    protected function deepWhitelist($key, array $result, array $data)
+    {
+        $parts = explode('.', $key);
+
+        $ref = &$result;
+        $dataRef = &$data;
+        foreach ($parts as $part) {
+            $ref = &$ref[$part];
+            $dataRef = &$dataRef[$part];
+        }
+
+        $ref = $dataRef;
+
+        return $result;
+    }
+
     /**
      * Filter all set fields with a global chain, recursively
      *
diff --git a/tests/FilterTest.php b/tests/FilterTest.php
index 2507cf5..c761c35 100644
--- a/tests/FilterTest.php
+++ b/tests/FilterTest.php
@@ -326,4 +326,61 @@ public function testRemoveNullOnAllMultidimensionalValues()
 
         $this->assertEquals(['test2' => 'test', 'test4' => 'test'], $result);
     }
+
+    /**
+     * Ensure the filter only returns the keys we specify on white list
+     */
+    public function testFilterWithWhiteList()
+    {
+        $this->filter->whiteList(['first_name']);
+
+        $result = $this->filter->filter([
+            'first_name' => 'john',
+            'spam' => 'spam'
+        ]);
+
+        $this->assertEquals(['first_name' => 'john'], $result);
+    }
+
+    /**
+     * Ensure the filter only returns the keys we specify on white list,
+     * this time using dot notation
+     */
+    public function testFilterWithWhiteListSubArrays()
+    {
+        $this->filter->whiteList([
+            'first_name',
+            'test1',
+            'test2.test',
+            'test2.test3.test'
+        ]);
+
+        $result = $this->filter->filter([
+            'first_name' => 'john',
+            'test1' => [
+                'test' => 'hi'
+            ],
+            'test2' => [
+                'test' => 'hi test2',
+                'test3' => [
+                    'test' => 'hi inner'
+                ],
+                'spam2' => 'spam' 
+            ],
+            'spam' => 'spam'
+        ]);
+
+        $this->assertEquals([
+            'first_name' => 'john',
+            'test1' => [
+                'test' => 'hi'
+            ],
+            'test2' => [
+                'test' => 'hi test2',
+                'test3' => [
+                    'test' => 'hi inner'
+                ]
+            ]
+        ], $result);
+    }
 }

From b2f078b6ecc8831447e4f93888ef55c4fd5f8cab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Albert=20Cansado=20Sol=C3=A0?= <albert.cansado@gmail.com>
Date: Thu, 22 Aug 2019 15:52:32 +0200
Subject: [PATCH 2/2] fix CS

---
 tests/FilterTest.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/FilterTest.php b/tests/FilterTest.php
index c761c35..a19dc1b 100644
--- a/tests/FilterTest.php
+++ b/tests/FilterTest.php
@@ -365,7 +365,7 @@ public function testFilterWithWhiteListSubArrays()
                 'test3' => [
                     'test' => 'hi inner'
                 ],
-                'spam2' => 'spam' 
+                'spam2' => 'spam'
             ],
             'spam' => 'spam'
         ]);