From 4682e0c104bd78a26546e48d97a83d58ce980b2a Mon Sep 17 00:00:00 2001
From: vrana <jakubv@fb.com>
Date: Wed, 3 Oct 2012 11:07:56 -0700
Subject: [PATCH] Warn against writing to undeclared properties

Summary:
I make this error quite often: I forget to declare a property I am writing to or I make a typo in it.
PHP implicitly creates a public property which I don't like.

I would much rather see a linter warning me against this than this runtime check but writing it is very difficult:

- We need to explore all parents of the class we are checking.
- It is even possible that children will declare that property but it's OK to treat this as error anyway.
- We can extend also builtin or external classes.
- It's somewhat doable for `$this` but even more complex for any `$obj` because we don't know the class of it.

This should catch significant part of these errors and I'm fine with that.

I don't plan escalating to exception because this error is not fatal and should not stop the application from working.

Test Plan: Loaded homepage, checked log.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3601
---
 src/aphront/AphrontController.php           |  5 +++++
 src/infrastructure/storage/lisk/LiskDAO.php | 11 +++++++++++
 src/view/AphrontView.php                    |  7 ++++++-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/aphront/AphrontController.php b/src/aphront/AphrontController.php
index 94f0071f18..8fc6a48d1d 100644
--- a/src/aphront/AphrontController.php
+++ b/src/aphront/AphrontController.php
@@ -61,4 +61,9 @@ abstract class AphrontController {
     return $this->currentApplication;
   }
 
+  public function __set($name, $value) {
+    phlog('Wrote to undeclared property '.get_class($this).'::$'.$name.'.');
+    $this->$name = $value;
+  }
+
 }
diff --git a/src/infrastructure/storage/lisk/LiskDAO.php b/src/infrastructure/storage/lisk/LiskDAO.php
index 80f7ef051f..a1e65df2ac 100644
--- a/src/infrastructure/storage/lisk/LiskDAO.php
+++ b/src/infrastructure/storage/lisk/LiskDAO.php
@@ -1796,4 +1796,15 @@ abstract class LiskDAO {
 
     throw new Exception("Unable to resolve method '{$method}'.");
   }
+
+  /**
+   * Warns against writing to undeclared property.
+   *
+   * @task   util
+   */
+  public function __set($name, $value) {
+    phlog('Wrote to undeclared property '.get_class($this).'::$'.$name.'.');
+    $this->$name = $value;
+  }
+
 }
diff --git a/src/view/AphrontView.php b/src/view/AphrontView.php
index 99196f28e1..23807285a8 100644
--- a/src/view/AphrontView.php
+++ b/src/view/AphrontView.php
@@ -1,7 +1,7 @@
 <?php
 
 /*
- * Copyright 2011 Facebook, Inc.
+ * Copyright 2012 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,4 +49,9 @@ abstract class AphrontView {
 
   abstract public function render();
 
+  public function __set($name, $value) {
+    phlog('Wrote to undeclared property '.get_class($this).'::$'.$name.'.');
+    $this->$name = $value;
+  }
+
 }