MSTEST0056: Use DisplayName property for test method display names

Cause

A test method attribute uses a string constructor argument instead of the DisplayName property.

Rule description

When specifying a custom display name for a test method, you should use the DisplayName property instead of passing a string as a constructor argument. In MSTest 4.0 and later, the string constructor argument is used for source information (caller file path) rather than display name, which is a breaking change from MSTest 3.x. Using the DisplayName property ensures your code works correctly and avoids potential confusion.

[TestClass]
public class TestClass
{
    [TestMethod("My Test Name")] // Violation
    public void TestMethod()
    {
        // Test code
    }
}

How to fix violations

Replace the constructor argument with the DisplayName property.

[TestClass]
public class TestClass
{
    [TestMethod(DisplayName = "My Test Name")]
    public void TestMethod()
    {
        // Test code
    }
}

When to suppress warnings

Do not suppress warnings from this rule. Using the DisplayName property is the only way to specify custom display names for test methods. If your intent is to explicitly pass a value for the caller file path parameter instead of setting a display name, you can suppress this warning, but this is rarely needed.

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 MSTEST0056
// The code that's violating the rule is on this line.
#pragma warning restore MSTEST0056

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

[*.{cs,vb}]
dotnet_diagnostic.MSTEST0056.severity = none

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