src/third_party/devtools/front_end/cm/README.md - cobalt - Git at Google

 # Rolling CodeMirror

 ## What's this about?
 CodeMirror is a third-party library, which supports editing experience in Chrome DevTools. DevTools does not fork CodeMirror, thus all CodeMirror patches should go upstream to http://codemirror.net.
 Every once in a while, the CodeMirror dependency (which is located in Source/devtools/front_end/cm/ folder) should be updated to a newer version.

 ## Updating CodeMirror

 Run `python devtools/scripts/roll_codemirror.js <codemirror_dir> <devtools_dir>`

 ## Manual steps
 This requires the following steps to be done:
 1. File `headlesscodemirror.js` is a `runmode-standalone.js` file from CodeMirror distribution, but wrapped in `(function(window) { ... }(this))`
 construction. This is needed to support in web workers.
 2. File `codemirror.css` contains both the default theme of CodeMirror and structural css required for it to work. Discard everything in the file up to the word `/* STOP */`.
 3. All other files in `front_end/cm/` folder should be substituted with their newer versions from the upstream.
 4. All files in `front_end/cm_web_modes/` and `front_end/cm_modes/` should be updated with newer versions from upstream.

 ## Testing
 DevTools wrap CodeMirror via `CodeMirrorTextEditor.js` and `cmdevtools.css` files.
 Although there are a couple of automated tests (web_tests/inspector/editor/) to verify overall sanity of the setup, a manual testing is mandatory before
 landing a roll. Here is a rough testing scenario outline:
 1. Create a new snippet and type in a small function with a few nested for-loops. (The author suggests a bubble-sort). Make sure that:
    * Words `function`, `for`, `var` are highlighted
    * "Smart braces" behavior works
    * "Enter" after opening curly brace adds correct indent
    * Autocompletion works
    * Multiple cursors functionality works as intended - Ctrl+D/Ctrl+U shortcuts
    * Set a breakpoint inside a function, select some text and summon a context menu over it.
 2. Make sure there are items such as "Add to Watch", "Evaluate in Console" and "Copy/Paste"
 Make sure minified jquery opens nicely in the editor (minified jquery could be found as a resource on http://jquery.com)
    * Verify `jquery.min.js` is formatted via "Pretty print" action
 3. Go to the Elements panel, select a node and verify the "Edit it as HTML" command works.

 ## Committing
 The only changes allowed to `front_end/cm/` folder are CodeMirror rolls. There's a presubmit check that enforces this, so make sure you include the phrase "roll CodeMirror" into
 your patch description.

 ## Example
 Example CodeMirror roll patchset: https://codereview.chromium.org/273763003
	# Rolling CodeMirror

	## What's this about?
	CodeMirror is a third-party library, which supports editing experience in Chrome DevTools. DevTools does not fork CodeMirror, thus all CodeMirror patches should go upstream to http://codemirror.net.
	Every once in a while, the CodeMirror dependency (which is located in Source/devtools/front_end/cm/ folder) should be updated to a newer version.

	## Updating CodeMirror

	Run `python devtools/scripts/roll_codemirror.js <codemirror_dir> <devtools_dir>`

	## Manual steps
	This requires the following steps to be done:
	1. File `headlesscodemirror.js` is a `runmode-standalone.js` file from CodeMirror distribution, but wrapped in `(function(window) { ... }(this))`
	construction. This is needed to support in web workers.
	2. File `codemirror.css` contains both the default theme of CodeMirror and structural css required for it to work. Discard everything in the file up to the word `/* STOP */`.
	3. All other files in `front_end/cm/` folder should be substituted with their newer versions from the upstream.
	4. All files in `front_end/cm_web_modes/` and `front_end/cm_modes/` should be updated with newer versions from upstream.

	## Testing
	DevTools wrap CodeMirror via `CodeMirrorTextEditor.js` and `cmdevtools.css` files.
	Although there are a couple of automated tests (web_tests/inspector/editor/) to verify overall sanity of the setup, a manual testing is mandatory before
	landing a roll. Here is a rough testing scenario outline:
	1. Create a new snippet and type in a small function with a few nested for-loops. (The author suggests a bubble-sort). Make sure that:
	* Words `function`, `for`, `var` are highlighted
	* "Smart braces" behavior works
	* "Enter" after opening curly brace adds correct indent
	* Autocompletion works
	* Multiple cursors functionality works as intended - Ctrl+D/Ctrl+U shortcuts
	* Set a breakpoint inside a function, select some text and summon a context menu over it.
	2. Make sure there are items such as "Add to Watch", "Evaluate in Console" and "Copy/Paste"
	Make sure minified jquery opens nicely in the editor (minified jquery could be found as a resource on http://jquery.com)
	* Verify `jquery.min.js` is formatted via "Pretty print" action
	3. Go to the Elements panel, select a node and verify the "Edit it as HTML" command works.

	## Committing
	The only changes allowed to `front_end/cm/` folder are CodeMirror rolls. There's a presubmit check that enforces this, so make sure you include the phrase "roll CodeMirror" into
	your patch description.

	## Example
	Example CodeMirror roll patchset: https://codereview.chromium.org/273763003