xRetry

Retry flickering test cases for xUnit and SpecFlow in dotnet core.

When to use this

This is intended for use on flickering tests, where the reason for failure is an external dependency and the failure is transient, e.g:

• HTTP request over the network
• Database call that could deadlock, timeout etc...

Whenever a test includes real-world infrastructure, particularly when communicated with via the internet, there is a risk of the test randomly failing so we want to try and run it again. This is the intended use case of the library.

If you have a test that covers some flaky code, where sporadic failures are caused by a bug, this library should not be used to cover it up!

Usage: SpecFlow 3

Add the xRetry.SpecFlow nuget package to your project.

Above any scenario that should be retried, add a @retry tag, e.g:

@retry
Scenario: Retry three times by default
	When I increment the default retry count
	Then the default result should be 3

This will retry the test up to 3 times by default. You can optionally specify a number of times to retry the test in brackets, e.g. @retry(5).

You can also optionally specify a delay between each retry (in milliseconds) as a second parameter, e.g. @retry(5,100) will run your test 5 times until it passes, waiting 100ms between each attempt.
Note that you must not include a space between the parameters, as Cucumber/SpecFlow uses a space to separate tags, i.e. @retry(5, 100) would not work due to the space after the comma.

Usage: xUnit

Add the xRetry nuget package to your project.

Above any Fact test case that should be retried, replace the Fact attribute, with RetryFact, e.g:

private static int defaultNumCalls = 0;

[RetryFact]
public void Default_Reaches3()
{
    defaultNumCalls++;

    Assert.Equal(3, defaultNumCalls);
}

This will retry the test up to 3 times by default. You can optionally specify a number of times to retry the test as an argument, e.g. [RetryFact(5)].

You can also optionally specify a delay between each retry (in milliseconds) as a second parameter, e.g. [RetryFact(5, 100)] will run your test 5 times until it passes, waiting 100ms between each attempt.

Contributing

Feel free to open a pull request! If you want to start any sizeable chunk of work, consider opening an issue first to discuss, and make sure nobody else is working on the same problem.

Running locally

To run locally, always build xRetry.SpecFlowPlugin before the tests, to ensure MSBuild uses the latest version of your changes.

If you install make and go to the build directory, you can run the following from the terminal to build, run tests and create the nuget packages:

make build unit-tests-run nuget-create

If that works, all is well!

Licence

MIT