Coyote is a testing library and tool that helps ensure that your C# code is free of annoying concurrency bugs.
It gives you the ability to reliably unit test the concurrency and other sources of nondeterminism (such as message re-orderings, timeouts and failures) in your C# code. In the heart of Coyote is a scheduler that takes control (via binary rewriting) of your program's concurrent execution during testing and is able to systematically explore the concurrency and nondeterminism to find bugs. The awesome thing is that once Coyote finds a bug it gives you the ability to fully reproduce it as many times as you want, making debugging and fixing the issue much easier.
Coyote is used by many teams in Azure to test their distributed systems and services, finding hundreds of concurrency-related bugs before they manifest in production. In the words of an Azure service architect:
Coyote found several issues early in the dev process, this sort of issues that would usually bleed through into production and become very expensive to fix later.
Coyote is made with ❤️ by Microsoft Research.
Getting started with Coyote is easy! Check out https://microsoft.github.io/coyote for tutorials, documentation, how-tos, samples and more information about the project. Enjoy!
This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.
When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repositories using our CLA.
This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.