codediff.js is a two-column JavaScript diff visualization with syntax highlighting and character-by-character differences.

It was originally based on jsdifflib, but has been rewritten almost entirely.

Try the online demo!

codediff.js is used by webdiff.

<!-- Third-party dependencies -->
<script src="jquery.min.js"></script>
<script src="highlight.min.js"></script>
<link rel="stylesheet" href="googlecode.css">  <!-- highlight.js theme -->

<!-- codediff -->
<script src="difflib.js"></script>
<script src="codediff.js"></script>
<link rel="stylesheet" href="codediff.css">

<!-- DOM -->
<p>Here's the diff!</p>    
<div id="diffview"></div>

<!-- Usage -->
<script type="text/javascript">
$('#diffview').append(
    codediff.buildView(codeBefore, codeAfter, {
        /* options -- see below */
    }));
</script>

Here are possible keys you can pass through the options parameter:

• language: Language to use for syntax highlighting. This parameter is passed through to highlight.js, which does the highlighting. Any value it will accept is fine. You can do hljs.getLanguage(language) to see if a language code is valid. A null value (the default) will disable syntax highlighting. Example values include "python" or "javascript". (default: null)
• beforeName: Text to place above the left side of the diff.
• afterName: Text to place above the right side of the diff.
• contextSize: Minimum number of lines of context to show around each diff hunk. (default: 3).
• minJumpSize: Minimum number of equal lines to collapse into a "Show N more lines" link. (default: 10)
• wordWrap: By default, code will go all the way to the right margin of the diff. If there are 60 characters of space, character 61 will wrap to the next line, even mid-word. To wrap at word boundaries instead, set this option.

Here's an example usage with a filled-out options parameter:

$('#diffview').append(
    codediff.buildView(codeBefore, codeAfter, {
        language: 'python',
        beforeName: 'oldfilename.py',
        afterName: 'newfilename.py',
        contextSize: 8,
        minJumpSize: 5,
        wordWrap: true
    }));

To iterate on the project locally, open one of the test*.html files.

To run the tests, run:

npm install
grunt test