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Standalone and test framework agnostic JavaScript test spies, stubs and mocks (pronounced "sigh-non", named after Sinon, the warrior).
For details on compatibility and browser support, please see COMPATIBILITY.md
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.
See CONTRIBUTING.md for details on how you can contribute to Sinon.JS. Artifact-first contract tests are used to protect public APIs during migration.
The lib/ directory is generated build output and is not committed to the repository; run npm run build to regenerate it locally when needed.
Thank you to all our backers! 🙏 [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
Jest is a complete testing framework that comes with spies, mocks, and stubs built-in. It is often compared to Sinon for its mocking capabilities, but Jest provides a more integrated experience with a test runner and assertion library included.
Testdouble.js (npm package 'testdouble') is a minimalistic testing library that provides a similar API to Sinon for creating test doubles like stubs, mocks, and spies. It focuses on providing a more user-friendly experience with better error messages and simpler APIs.
Chai-spies is a plugin for the Chai assertion library that adds spy capabilities. While it doesn't offer as comprehensive a set of features as Sinon, it integrates well with Chai for developers who prefer that assertion style.
FAQs
JavaScript test spies, stubs and mocks.
The npm package sinon receives a total of 9,870,898 weekly downloads. As such, sinon popularity was classified as popular.
We found that sinon demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 4 open source maintainers collaborating on the project.
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Company News
Socket won two 2026 Reppy Awards from RepVue, ranking in the top 5% of all sales orgs. AE Alexandra Lister shares what it's like to grow a sales career here.

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NIST will stop enriching most CVEs under a new risk-based model, narrowing the NVD's scope as vulnerability submissions continue to surge.

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Socket is an initial recipient of OpenAI's Cybersecurity Grant Program, which commits $10M in API credits to defenders securing open source software.