Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Syntactically-aware grep for JavaScript
JavaScript
branch: master

Fetching latest commit…

Cannot retrieve the latest commit at this time

Failed to load latest commit information.
bin
lib
narcissus @ 835c141
specs
tests
.gitignore
.gitmodules
LICENSE License headers
README.mdown
package.json

README.mdown

Archived Repo

This is an archived project and is no longer supported or updated by Facebook. Please do not file issues or pull-requests against this repo. If you wish to continue to develop this code yourself, we recommend you fork it.

Proceed and be bold!

jsgrep / jspatch - toolkit for searching and modifying JavaScript

Jsgrep is program that searches for a particular JavaScript pattern using the abstract syntax tree (AST) of the program. This enables matching expressions based on their JavaScript meaning, rather than based on simple strings. Jspatch is a tool to take that information and programmatically modify the original source code.

Example

Jsgrep: find Javelin classes that have a 'path' property

$ jsgrep -p C "JX.install(C, { properties: { path: X } })" tests/*.js
tests/javelin.js: 'Event'
tests/javelin.js: 'URI'

Jsgrep allows easily drilling into the structure of JavaScript classes. In this example, jsgrep finds Javelin classes that contain a 'path' property. The class name is stored in the metavariable C, which will be output.

Jspatch: replace setTimeout with window.setTimeout in jQuery

$ jspatch -e 's/setTimeout( A, B )/window.setTimeout( A, B )/' tests/jquery.js
--- tests/jquery.js 2012-01-10 14:51:36.000000000 -0800
+++ /tmp/jspatch.jquery.js  2012-01-11 17:13:56.000000000 -0800
@@ -420,7 +420,7 @@
        if ( (wait === true && !--jQuery.readyWait) || (wait !== true && !jQuery.isReady) ) {
            // Make sure body exists, at least, in case IE gets a little overzealous (ticket #5443).
            if ( !document.body ) {
-               return setTimeout( jQuery.ready, 1 );
+               return window.setTimeout( jQuery.ready, 1 );
            }

            // Remember that the DOM is ready
@@ -1987,7 +1987,7 @@
        ( src === "mark" || !jQuery._data(elem, markDataKey) ) ) {
        // Give room for hard-coded callbacks to fire first
        // and eventually mark/queue something else on the element
-       setTimeout( function() {
+       window.setTimeout( function() {
            if ( !jQuery._data( elem, queueDataKey ) &&
                !jQuery._data( elem, markDataKey ) ) {
                jQuery.removeData( elem, deferDataKey, true );

Jspatch supports a versatile patch file format that can perform far more complex transformations as well. For more information, see the online documentation.

Installation

npm install jsgrep-toolkit

To install from source code:

git clone https://github.com/facebook/jsgrep.git
cd jsgrep
git submodule update --init
npm install

TODO

  • Consider a metavar that matches but doesn't save, to prevent ambiguities.
  • Rewrite forEachNode to be iterative rather than recursive (to fix ...)
  • Consider support for --where/--eval and/or not-patterns
  • Support for most statements in patterns
  • Formally testing the pattern matchers

jspatch:

  • Testing

Contributors

Jsgrep was written by Ryan Patterson at Facebook. Inspiration for this project draws heavily from pfff, a source code analyzer written at Facebook.

Something went wrong with that request. Please try again.