Note from maintainers Since Jest supports snapshot testing, we recommend you to use that instead of expect-jsx.

expect-jsx is no more compatible with recent Jest versions (22), it can be made compatible so feel free to open a PR if so.

expect-jsx

toEqualJSX for mjackson/expect.

It uses algolia/react-element-to-jsx-string in the background to turn React elements into formatted strings.

Table of Contents generated with DocToc

• Setup
• API
• Usage
• A note about functions
• Environment requirements
• Test
• Build
• Release
• Similar projects
• Thanks

Setup

You will most probably use this plugin as a development dependency.

yarn add expect-jsx --dev

API

• expect(ReactComponent|JSX).toEqualJSX(ReactComponent|JSX)
• expect(ReactComponent|JSX).toNotEqualJSX(ReactComponent|JSX)
• expect(ReactComponent|JSX).toIncludeJSX(ReactComponent|JSX)
• expect(ReactComponent|JSX).toNotIncludeJSX(ReactComponent|JSX)

Usage

Here's an example using mochajs/mocha.

import React from 'react';
import expect from 'expect';
import expectJSX from 'expect-jsx';

expect.extend(expectJSX);

class TestComponent extends React.Component {}

describe('expect-jsx', () => {
  it('works', () => {
    expect(<div />).toEqualJSX(<div />);
    // ok

    expect(<div a="1" b="2" />).toEqualJSX(<div />);
    // Error: Expected '<div\n  a="1"\n  b="2"\n/>' to equal '<div />'

    expect(<span />).toNotEqualJSX(<div/>);
    // ok

    expect(<div><TestComponent /></div>).toIncludeJSX(<TestComponent />);
    // ok
  });
});

It looks like this when ran:

A note about functions

toEqualJSX will not check for function references, it only checks that if a function was expected somewhere, there's also a function in the actual data.

It's your responsibility to then unit test those functions.

Environment requirements

The environment you use to use react-element-to-jsx-string should have ES2015 support.

Use the Babel polyfill or any other method that will make you environment behave like an ES2015 environment.

Test

yarn test
yarn test:watch

Build

yarn build
yarn build:watch

Release

Decide if this is a patch, minor or major release, look at http://semver.org/

yarn release [major|minor|patch|x.x.x]

Similar projects

There are multiple similar projects for other assertions libraries, all based on algolia/react-element-to-jsx-string. For instance:

• chai-equal-jsx, assertions for chai: expect(<div />).to.equalJSX(<div />);
• chai-jsx, assertions for chai: expect(<div />).jsx.to.equal(<div />);
• jsx-chai, assertions for chai: expect(<div />).to.deep.equal(<div />);
• tape-jsx-equals, assertions for tape: t.jsxEquals(<div />, <div />);
• jasmine-expect-jsx, assertions for jasmine: expect(<div />).toEqualJSX(<div />);

Thanks

To the people pointing me in the right directions like:

• https://github.com/facebook/react/issues/4835
• https://github.com/mjackson/expect/issues/37