Diff XML documents

The goal of this module is to calculate diff between text content of two XML or HTML documents, preserving its tag structure:

import diff from '@emmetio/xml-diff';

const from = `<doc>
    <p>Lorem ipsum dolor sit amet <em>consectetur, adipisicing</em> elit.</p>
</doc>`;
const to = `<doc>
    <p>Lorem ipsum dolor sit amet aspernatur, <strong>doloribus</strong> in libero.</p>
</doc>`;

const result = diff(from, to);
console.log(result);
/*
<doc>
    <p>Lorem ipsum dolor sit amet <del>consectetur, adipisicing elit</del><ins>aspernatur, </ins><strong><ins>doloribus</ins></strong><ins> in libero</ins>.</p>
</doc>
*/

Project development is sponsored by Xcential Corporation

Features

High performance: uses small and fast XML scanner, written in pure JavaScript.
Supports multiple dialects: able to parse invalid HTML, even JSX and Angular templates.
Works everywhere: doesn’t use browser DOM or APIs, runs in any browser, Node.JS and WebWorkers.

Installation & usage

Install it as regular npm module:

npm install @emmetio/xml-diff

This module exposes main diff(from, to) function which accepts two text documents and returns patched to document with updates marked with <ins> and <del> tags.

How it works

Takes XML document and strips all markup data from it (tags, comments, CDATA etc.), leaving plain text content: <div>Hello <b>world</b>!</div> → Hello world!.
Collapses and reduces insignificant white space characters like new lines, tabs and so on into a single space to reduce noise when comparing formatted documents.
Performs diff with Google’s Diff Match Patch library.
Applies patches to second document’s (to) plain content.
Restores markup and whitespace data of original document