Jest-style diffs on Chai equalities

(Based upon chai-jest-diff)

Chai’s assertions have a built-in showDiff flag, but do not produce the diff themselves; it’s up to the test runner to produce such output.

The very popular Mocha does that, but Jest doesn’t: its neat diffs are produced internally by its built-in matchers; it doesn’t rely on any sort of metadata to produce diff for third-party assertions.

This Chai plugin tries to fix that, piggybacking on Jest’s jest-diff and jest-matcher-utils for maximum compatibility with Jest’s built-in expectation output.

Usage

const chai = require('chai');
const chaiSubset = require('chai-subset');
const chaiSubsetJestDiff = require('chai-jest-diff');

chai.use(chaiSubset);
chai.use(chaiJestDiff());

Options

The plugin factory accepts a boolean argument, expand, that mirrors Jest’s expand configuration setting, for full-length diffs (instead of close-context diffs).

Contributing

Contributions are welcome. Please submit a pull request and include tests.

Please follow the coding style in .editorconfig

Contributions should pass npm test

Testing

Run npm test

License

© 2017 Agency Ventures Original framework © 2017 Delicious Insights

This plugin is provided under the MIT license. See LICENSE.md for details.