jsdiff
![Sauce Test Status](https://saucelabs.com/buildstatus/jsdiff)
A javascript text differencing implementation.
Based on the algorithm proposed in
"An O(ND) Difference Algorithm and its Variations" (Myers, 1986).
Installation
npm install diff
or
bower install jsdiff
API
-
JsDiff.diffChars(oldStr, newStr[, callback])
- diffs two blocks of text, comparing character by character.
Returns a list of change objects (See below).
-
JsDiff.diffWords(oldStr, newStr[, callback])
- diffs two blocks of text, comparing word by word, ignoring whitespace.
Returns a list of change objects (See below).
-
JsDiff.diffWordsWithSpace(oldStr, newStr[, callback])
- diffs two blocks of text, comparing word by word, treating whitespace as significant.
Returns a list of change objects (See below).
-
JsDiff.diffLines(oldStr, newStr[, callback])
- diffs two blocks of text, comparing line by line.
Returns a list of change objects (See below).
-
JsDiff.diffTrimmedLines(oldStr, newStr[, callback])
- diffs two blocks of text, comparing line by line, ignoring leading and trailing whitespace.
Returns a list of change objects (See below).
-
JsDiff.diffSentences(oldStr, newStr[, callback])
- diffs two blocks of text, comparing sentence by sentence.
Returns a list of change objects (See below).
-
JsDiff.diffCss(oldStr, newStr[, callback])
- diffs two blocks of text, comparing CSS tokens.
Returns a list of change objects (See below).
-
JsDiff.diffJson(oldObj, newObj[, callback])
- diffs two JSON objects, comparing the fields defined on each. The order of fields, etc does not matter in this comparison.
Returns a list of change objects (See below).
-
JsDiff.createTwoFilesPatch(oldFileName, newFileName, oldStr, newStr, oldHeader, newHeader)
- creates a unified diff patch.
Parameters:
oldFileName
: String to be output in the filename section of the patch for the removalsnewFileName
: String to be output in the filename section of the patch for the additionsoldStr
: Original string valuenewStr
: New string valueoldHeader
: Additional information to include in the old file headernewHeader
: Additional information to include in thew new file headeroptions
: An object with options. Currently, only context
is supported and describes how many lines of context should be included.
-
JsDiff.createPatch(fileName, oldStr, newStr, oldHeader, newHeader)
- creates a unified diff patch.
Just like JsDiff.createTwoFilesPatch, but with oldFileName being equal to newFileName.
-
JsDiff.structuredPatch(oldFileName, newFileName, oldStr, newStr, oldHeader, newHeader, options)
- returns an object with an array of hunk objects.
This method is similar to createTwoFilesPatch, but returns a data structure
suitable for further processing. Parameters are the same as createTwoFilesPatch. The data structure returned may look like this:
{
oldFileName: 'oldfile', newFileName: 'newfile',
oldHeader: 'header1', newHeader: 'header2',
hunks: [{
oldStart: 1, oldLines: 3, newStart: 1, newLines: 3,
lines: [' line2', ' line3', '-line4', '+line5', '\\ No newline at end of file'],
}]
}
-
JsDiff.applyPatch(oldStr, diffStr)
- applies a unified diff patch.
Return a string containing new version of provided data.
-
convertChangesToXML(changes)
- converts a list of changes to a serialized XML format
All methods above which accept the optional callback method will run in sync mode when that parameter is omitted and in async mode when supplied. This allows for larger diffs without blocking the event loop.
Change Objects
Many of the methods above return change objects. These objects are consist of the following fields:
value
: Text contentadded
: True if the value was inserted into the new stringremoved
: True of the value was removed from the old string
Note that some cases may omit a particular flag field. Comparison on the flag fields should always be done in a truthy or falsy manner.
Examples
Basic example in Node
require('colors')
var jsdiff = require('diff');
var one = 'beep boop';
var other = 'beep boob blah';
var diff = jsdiff.diffChars(one, other);
diff.forEach(function(part){
var color = part.added ? 'green' :
part.removed ? 'red' : 'grey';
process.stderr.write(part.value[color]);
});
console.log()
Running the above program should yield
Basic example in a web page
<pre id="display"></pre>
<script src="diff.js"></script>
<script>
var one = 'beep boop';
var other = 'beep boob blah';
var diff = JsDiff.diffChars(one, other);
diff.forEach(function(part){
var color = part.added ? 'green' :
part.removed ? 'red' : 'grey';
var span = document.createElement('span');
span.style.color = color;
span.appendChild(document
.createTextNode(part.value));
display.appendChild(span);
});
</script>
Open the above .html file in a browser and you should see
Full online demo
Compatibility
![Sauce Test Status](https://saucelabs.com/browser-matrix/jsdiff.svg)
jsdiff supports all ES3 environments with some known issues on IE8 and below. Under these browsers some diff algorithms such as word diff and others may fail due to lack of support for capturing groups in the split
operation.
License
See LICENSE.