Mocha provides developers with a base test framework, allowing you to have options as to which assertion, moking and spy libraries you want to use. Chai is one of the popular open-source assertion libraries used with Mocha.

References

  • https://amzotti.github.io/testing/2015/03/16/what-is-the-difference-between-a-test-runner-testing-framework-assertion-library-and-a-testing-plugin/
  • https://blog.usejournal.com/jest-vs-mocha-whats-the-difference-235df75ffdf3