Microsoft.Coyote.Tool
1.7.11
Prefix Reserved
dotnet add package Microsoft.Coyote.Tool --version 1.7.11
NuGet\Install-Package Microsoft.Coyote.Tool -Version 1.7.11
<PackageReference Include="Microsoft.Coyote.Tool" Version="1.7.11" />
paket add Microsoft.Coyote.Tool --version 1.7.11
#r "nuget: Microsoft.Coyote.Tool, 1.7.11"
// Install Microsoft.Coyote.Tool as a Cake Addin #addin nuget:?package=Microsoft.Coyote.Tool&version=1.7.11 // Install Microsoft.Coyote.Tool as a Cake Tool #tool nuget:?package=Microsoft.Coyote.Tool&version=1.7.11
Coyote
Coyote is a cross-platform library and tool for testing concurrent C# code and deterministically reproducing bugs.
Using Coyote, you can easily test the concurrency and other nondeterminism in your C# code, by writing what we call a concurrency unit test. These look like your regular unit tests, but can reliably test concurrent workloads (such as actors, tasks, or concurrent requests to ASP.NET controllers). In regular unit tests, you would typically avoid concurrency due to flakiness, but with Coyote you are encouraged to embrace concurrency in your tests to find bugs.
Coyote is used by many teams in Azure to test their distributed systems and services, and has found hundreds of concurrency-related bugs before deploying code in production and affecting users. 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.
How it works
Consider the following simple test:
[Fact]
public async Task TestTask()
{
int value = 0;
Task task = Task.Run(() =>
{
value = 1;
});
Assert.Equal(0, value);
await task;
}
This test will pass most of the time because the assertion will typically execute before the task
starts, but there is one schedule where the task starts fast enough to set value
to 1
causing
the assertion to fail. Of course, this is a very naive example and the bug is obvious, but you could
imagine much more complicated race conditions that are hidden in complex execution paths.
The way Coyote works, is that you first convert the above test to a concurrency unit test using the
Coyote TestingEngine
API:
using Microsoft.Coyote.SystematicTesting;
[Fact]
public async Task CoyoteTestTask()
{
var configuration = Configuration.Create().WithTestingIterations(10);
var engine = TestingEngine.Create(configuration, TestTask);
engine.Run();
}
Next, you run the coyote rewrite
command from the CLI (typically as a post-build task) to
automatically rewrite the IL of your test and production binaries. This allows Coyote to inject
hooks that take control of the concurrent execution during testing.
You can then run the concurrent unit test from your favorite unit testing framework (such as
xUnit). Coyote will take over and repeatedly execute the test from
beginning to the end for N iterations (in the above example N was configured to 10
). Under the
hood, Coyote uses intelligent search strategies to explore all kinds of execution paths that might
hide a bug in each iteration.
The awesome thing is that once a bug is found, Coyote gives you a trace through the engine.TestReport
API that you can use to reliably reproduce the bug as many times as you want, making debugging and
fixing the issue significantly easier.
Get started
Getting started with Coyote is easy! First, follow this
guide to install the coyote
command-line tool from NuGet. You are now ready
to check out the Coyote website for tutorials, documentation,
how-tos, samples and more information about the project. Enjoy!
Upgrading your coyote
dependencies? Check the changelog here.
Support
Note that Coyote is an open-source project that is provided "as-is". We are not able to provide any formal support. For Microsoft employees we have the Friends of Coyote Teams channel, which is an internal community that can help answer questions and learn from each other.
Contributing
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.
Code of Conduct
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.
Product | Versions Compatible and additional computed target framework versions. |
---|---|
.NET | net5.0 was computed. net5.0-windows was computed. net6.0 is compatible. net6.0-android was computed. net6.0-ios was computed. net6.0-maccatalyst was computed. net6.0-macos was computed. net6.0-tvos was computed. net6.0-windows was computed. net7.0 was computed. net7.0-android was computed. net7.0-ios was computed. net7.0-maccatalyst was computed. net7.0-macos was computed. net7.0-tvos was computed. net7.0-windows was computed. net8.0 is compatible. net8.0-android was computed. net8.0-browser was computed. net8.0-ios was computed. net8.0-maccatalyst was computed. net8.0-macos was computed. net8.0-tvos was computed. net8.0-windows was computed. |
.NET Core | netcoreapp3.1 is compatible. |
.NET Framework | net462 is compatible. net463 was computed. net47 was computed. net471 was computed. net472 was computed. net48 was computed. net481 was computed. |
-
.NETCoreApp 3.1
- No dependencies.
-
.NETFramework 4.6.2
- No dependencies.
-
net6.0
- No dependencies.
-
net8.0
- No dependencies.
NuGet packages
This package is not used by any NuGet packages.
GitHub repositories (1)
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