MSTEST0001: Explicitly enable or disable tests parallelization
| Property | Value |
|---|---|
| Rule ID | MSTEST0001 |
| Title | Explicitly enable or disable tests parallelization |
| Category | Performance |
| Fix is breaking or non-breaking | Non-breaking |
| Enabled by default | Yes |
| Default severity | Info |
| Introduced in version | 3.2.0 |
| Is there a code fix | No |
Cause
The assembly is not marked with [assembly: Parallelize] or [assembly: DoNotParallelize] attribute.
Rule description
By default, MSTest runs tests within the same assembly sequentially, which can lead to severe performance limitations. It is recommended to enable assembly attribute [assembly: Parallelize] to run tests in parallel, or if the assembly is known to not be parallelizable, to use explicitly the assembly level attribute [assembly: DoNotParallelize].
The default configuration of [assembly: Parallelize] is equivalent to [assembly: Parallelize(Scope = ExecutionScope.ClassLevel)], meaning that the parallelization will be set at class level (not method level) and will use as many threads as possible (depending on internal implementation).
How to fix violations
To fix a violation of this rule, add [assembly: Parallelize] or [assembly: DoNotParallelize] attribute. We recommend to use [assembly: Parallelize(Scope = ExecutionScope.MethodLevel)] to have best parallelization.
When to suppress warnings
Do not suppress a warning from this rule. Many libraries can benefit from a massive performance boost when enabling parallelization. When the test application is designed in a way that prevents parallelization, having the attribute explicitly set helps new developers to understand the limitations of the library.
Suppress a warning
Violations to this rule cannot be suppressed inline.
To disable the rule for a file, folder, or project, set its severity to none in the configuration file.
[*.{cs,vb}]
dotnet_diagnostic.MSTEST0001.severity = none
For more information, see How to suppress code analysis warnings.
