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Standalone and test framework agnostic JavaScript test spies, stubs and mocks (pronounced "sigh-non", named after Sinon, the warrior).

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via npm

$ npm install sinon

or via sinon's browser builds available for download on the homepage. There are also npm based CDNs one can use.


See the sinon project homepage for documentation on usage.

If you have questions that are not covered by the documentation, you can check out the sinon tag on Stack Overflow or drop by #sinon.js on

You can also search through the Sinon.JS mailing list archives.


  • No global pollution
  • Easy to use
  • Require minimal “integration”
  • Easy to embed seamlessly with any testing framework
  • Easily fake any interface
  • Ship with ready-to-use fakes for XMLHttpRequest, timers and more


See for details on how you can contribute to Sinon.JS


Support us with a monthly donation and help us continue our activities. [Become a backer]


Become a sponsor and get your logo on our README on GitHub with a link to your site. [Become a sponsor]


Sinon.js was released under BSD-3