chai-html

A focussed HTML assertions plugin for Chai.

Installation

This is a Node.js module available through the npm registry. Node.js 18 or higher is required.

$ npm install --save-dev chai-html

👋 Please note this package is for Chai v5 and is ESM only. For Chai v4 and CommonJS support use version 2 of this package.

Usage

import { use, expect } from 'chai'
import chaiHtml from 'chai-html'

// Register the plugin
use(chaiHtml)

// Write assertions!
expect('<div><img /></div>').html.to.equal('<div><img></div>')
expect('<h1>Hello World!</h1>').html.to.not.equal('<h1>Hallo Welt!</h1>')

HTML assertions will throw an error directing you to the change, so instead of squinting at a long HTML string you'll get something useful:

expect('<img />').html.to.equal('<br />')
// throws: tag <img> was changed to tag <br>

expect('<img src="..." />').html.to.equal('<img src="..." alt="..." />')
// throws: attribute [alt="..."] has been added

expect('<p>Hello World!</p> Hej!').html.to.equal('<p>Hello World!</p>')
// throws: text " Hej!" has been removed

.ignoringComments

Add the ignoringComments flag to the chain to ignore HTML comments.

expect('<div><!--Comment--></div>').html.ignoringComments.to.equal('<div></div>')

How does it work?

Underneath this plugin uses parse5 to parse the given HTML strings and normalize the generated trees before being compared. This means that although the two strings of markup may not be the same they should generate equivalent structures.

Credits

This plugin is inspired by the similar chai-xml plugin.

License

This package is MIT licensed.