Karl Jones: /* See also */

2016-11-29T18:42:45Z

‎See also

Karl Jones: /* Quotes */

2016-11-29T18:42:22Z

‎Quotes

Karl Jones: Created page with "A '''monkey patch''' is a way for a computer program to extend or modify supporting system software locally (affecting only the running instance of the program). == Appli..."

2016-11-29T18:39:39Z

Created page with "A '''monkey patch''' is a way for a computer program to extend or modify supporting system software locally (affecting only the running instance of the program). == Appli..."

New page

A '''monkey patch''' is a way for a [[computer program]] to extend or modify supporting system software locally (affecting only the running instance of the program).

== Applications ==

Monkey patching is used to:

* Replace methods / attributes / functions at runtime, e.g. to stub out a function during testing;
* Modify/extend behavior of a third-party product without maintaining a private copy of the source code;
* Apply a patch at runtime to the objects in memory, instead of the source code on disk;
* Distribute security or behavioral fixes that live alongside the original source code (an example of this would be distributing the fix as a plugin for the Ruby on Rails platform).

== Pitfalls ==

Carelessly written or poorly documented monkey patches can lead to problems:

* They can lead to upgrade problems when the patch makes assumptions about the patched object that are no longer true; if the product you have changed changes with a new release it may very well break your patch. For this reason monkey patches are often made conditional, and only applied if appropriate.
* If two modules attempt to monkey patch the same method, one of them (whichever one runs last) "wins" and the other patch has no effect, unless monkey patches are written with a pattern like alias_method_chain.
* They create a discrepancy between the original source code on disk and the observed behaviour that can be very confusing to anyone unaware of the patches' existence.

== Quotes ==

If it walks like a duck and talks like a duck, it’s a duck, right? So if this duck is not giving you the noise that you want, you’ve got to just punch that duck until it returns what you expect. -Patrick Ewing on Monkey/Duck patching in RailsConf 2007.[6]

== See also ==

* [[Aspect-oriented programming
* [[Self-modifying code
* [[Extension method]] in C#
* [[Category]] in Objective-C

== External links ==

* [https://en.wikipedia.org/wiki/Monkey_patch Monkey patch] @ Wikipedia

[[Category:Computer programming]]

@@ Line 26: / Line 26: @@
 == See also ==
-* [[Aspect-oriented programming
+* [[Aspect-oriented programming]]
-* [[Self-modifying code
+* [[Self-modifying code]]
 * [[Extension method]] in C#
-* [[Category]] in Objective-C
+* Category in Objective-C
 == External links ==

@@ Line 20: / Line 20: @@
 == Quotes ==
-If it walks like a duck and talks like a duck, it’s a duck, right? So if this duck is not giving you the noise that you want, you’ve got to just punch that duck until it returns what you expect. -Patrick Ewing on Monkey/Duck patching in RailsConf 2007.[6]
+"If it walks like a duck and talks like a duck, it’s a duck, right? So if this duck is not giving you the noise that you want, you’ve got to just punch that duck until it returns what you expect."
 == See also ==

Monkey patch - Revision history

Karl Jones: /* See also */

Karl Jones: /* Quotes */

Karl Jones: Created page with "A '''monkey patch''' is a way for a computer program to extend or modify supporting system software locally (affecting only the running instance of the program). == Appli..."