MSTEST0049: Flow TestContext cancellation token

Cause

A method call within a test context doesn't use the CancellationToken available from TestContext when the called method has a parameter or overload that accepts a CancellationToken.

Rule description

When TestContext is available in your test methods, you should flow its CancellationToken to async operations. This enables cooperative cancellation when timeouts occur and ensures proper resource cleanup. The TestContext cancellation token is especially important when using cooperative cancellation with timeout attributes.

This rule triggers when:

• A method call has an optional CancellationToken parameter that isn't explicitly provided.
• A method call has an overload that accepts a CancellationToken but the non-cancellable overload is used instead.

How to fix violations

Use the provided code fixer to automatically pass the CancellationToken from TestContext to method calls that support cancellation. You can also manually update method calls to include TestContext.CancellationToken as a parameter.

When to suppress warnings

Suppress this warning if you intentionally don't want to support cancellation for specific operations, or if the operation should continue even when the test is cancelled.