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MSTEST0084: Platform compatibility attributes should be consistent with '[OSCondition]'

Property Value
Rule ID MSTEST0084
Title Platform compatibility attributes should be consistent with [OSCondition]
Category Usage
Fix is breaking or non-breaking Non-breaking
Enabled by default Yes
Default severity Info
Introduced in version 4.5.0
Is there a code fix Yes, for C# only

Cause

An MSTest class or method uses SupportedOSPlatformAttribute or UnsupportedOSPlatformAttribute, but its MSTest OSConditionAttribute doesn't express a compatible operating-system condition.

Rule description

Platform compatibility attributes inform compile-time analysis, but they don't control whether MSTest runs a test. Without a compatible [OSCondition], a test can execute on an unsupported operating system and fail before it reaches the behavior that it intends to verify.

[TestMethod]
[SupportedOSPlatform("windows")]
public void UsesWindowsApi() { } // Violation

The rule accounts for platform compatibility attributes on the test, its containing types, and its assembly. A compatible class-level [OSCondition] can satisfy the requirement for a test method. If both the class and method declare [OSCondition], their combined conditions must match the effective platform restriction.

The rule compares operating-system families, not platform versions. For example, [SupportedOSPlatform("windows10.0")] still requires a condition for the Windows family, but [OSCondition] doesn't enforce the minimum Windows version. The analyzer doesn't report versioned [UnsupportedOSPlatform] restrictions because excluding an entire operating-system family would also skip supported versions.

How to fix violations

Keep the platform compatibility attribute for API analysis, and add or update [OSCondition] so MSTest skips the test on unsupported operating-system families.

[TestMethod]
[SupportedOSPlatform("windows")]
[OSCondition(OperatingSystems.Windows)]
public void UsesWindowsApi() { }

A C# code fix adds or updates [OSCondition] when the analyzer can determine a compatible condition. The analyzer reports a diagnostic without a fix when, for example, a method's class-level condition conflicts with its platform attributes, the platform isn't represented by OperatingSystems, or the platform attributes mix supported and unsupported restrictions. Resolve those conflicts manually. Visual Basic reports the diagnostic but doesn't provide an automatic fix.

When to suppress warnings

Suppress the rule when another mechanism guarantees that the test can't run on an incompatible operating system and adding [OSCondition] would duplicate that policy.

Suppress a warning

#pragma warning disable MSTEST0084
// The code that's violating the rule is on this line.
#pragma warning restore MSTEST0084

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

[*.{cs,vb}]
dotnet_diagnostic.MSTEST0084.severity = none

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

See also

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