Rediger

MSTEST0009: TestCleanup method should have valid layout

Property Value
Rule ID MSTEST0009
Title TestCleanup method should have valid layout
Category Usage
Fix is breaking or non-breaking Non-breaking
Enabled by default Yes
Default severity Warning
Introduced in version 3.3.0
Is there a code fix Yes

Cause

A method marked with [TestCleanup] should have valid layout.

Rule description

MSTest calls [TestCleanup] on the test-class instance after the test method. The callback releases or restores that test's state:

Requirement Reason
The method is public. Public methods form MSTest's lifecycle discovery contract. [DiscoverInternals] permits an internal declaring class, not an internal lifecycle method.
The method isn't static. Cleanup needs access to the instance fields and TestContext of the test that just ran.
The method is ordinary and isn't abstract. MSTest needs a callable method body, not a special member with language-defined invocation rules.
The method isn't generic. Lifecycle callbacks don't receive test-data arguments from which MSTest could infer method type arguments.
The method has no parameters. MSTest invokes this callback without arguments. Use the instance's TestContext for per-test information.
The return type is void, Task, or ValueTask. An awaitable return value lets MSTest finish asynchronous cleanup before it proceeds with the remaining lifecycle steps.
The method isn't async void. Without an awaitable result, cleanup could outlive the test lifecycle, and later exceptions couldn't be reliably recorded as cleanup failures.

The declaring type supplies the test fixture that owns these callbacks:

  • Use a class so MSTest can associate the callbacks with a test-class hierarchy.
  • Use a public class, or an internal class with [assembly: DiscoverInternals], to meet MSTest's type-discovery contract.
  • Use a non-static class for these fixtures. Test methods need a test-class instance, even when a class-level lifecycle callback is static.
  • Mark a sealed class with [TestClass] or a derived attribute. A sealed class can't supply inherited callbacks to another test class, so it must identify itself as the test container.

How to fix violations

Ensure that the method matches the layout described above.

When to suppress warnings

Do not suppress a warning from this rule. If you ignore this rule, flagged instances will be either skipped or result in runtime error.

Suppress a warning

If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.

#pragma warning disable MSTEST0009
// The code that's violating the rule is on this line.
#pragma warning restore MSTEST0009

To disable the rule for a file, folder, or project, set its severity to none in the configuration file.

[*.{cs,vb}]
dotnet_diagnostic.MSTEST0009.severity = none

For more information, see How to suppress code analysis warnings.