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MSTest code analysis

MSTest analysis ("MSTESTxxxx") rules inspect your C# or Visual Basic code for security, performance, design and other issues.

Tip

If you're using Visual Studio, many analyzer rules have associated code fixes that you can apply to correct the problem. Code fixes are shown in the light bulb icon menu.

The rules are organized into categories such as performance usage...

Starting with MSTest.TestFramework 3.7, the MSTest.Analyzers NuGet package is a dependency of the framework. For earlier versions, you need to use MSTest metapackage or add a package reference for MSTest.Analyzers explicitly.

MSTestAnalysisMode

Starting with MSTest 3.8, an MSBuild property named MSTestAnalysisMode is available to determine which analyzers are enabled at which severity.

Tip

To see which rules are enabled at which severity for each mode, you can navigate to the package of the version of interest in NuGet cache, locate the globalconfigs directory, and open the .globalconfig file corresponding to the analysis mode. For more information on finding the NuGet cache directory, see Managing the global packages, cache, and temp folders. From that directory, locate mstest.analyzers directory, then the version (3.8 and higher), then globalconfigs. Alternatively, you can download the NuGet package of the version of interest from nuget.org and view it in NuGet Package Explorer (Windows app), or view directly in the web app version of NuGet Package Explorer.

The available values for this property:

None

This value sets all analyzers to none severity, disabling all of them. You can then enable individual analyzers using .editorconfig or .globalconfig files.

Default

This setting follows the default documented behavior for each rule.

  • Rules that are enabled by default will use their default severity.
  • Rules that are disabled by default will use none severity.

Note

Rules that are enabled by default as warnings are violations that are expected to cause issues at runtime.

This is the mode most developers are expected to use. Rules that are enabled by default with Info (suggestion) severity are escalated to warnings. The following rules are escalated to errors in both Recommended and All modes:

All

This mode is more aggressive than Recommended. All rules are enabled as warnings. In addition, the following rules are escalated to errors:

Note

The following rules are completely opt-in and are not enabled in Default, Recommended, or All modes:

Rules by category

The analyzer rules are organized into the following categories:

Design rules

Design rules help you create and maintain test suites that adhere to proper design and good practices.

Performance rules

Performance rules support high-performance testing.

Suppression rules

Suppression rules support suppressing diagnostics from other rules.

Usage rules

Usage rules support proper usage of MSTest.

Rules by concept

Find rules organized by common testing scenarios and concepts:

Test structure & attributes

Rules that help ensure your test classes and methods are properly structured and decorated:

  • MSTEST0002 - Test class should be valid
  • MSTEST0003 - Test method should be valid
  • MSTEST0004 - Public types should be test classes
  • MSTEST0007 - Use attribute on test method
  • MSTEST0016 - Test class should have test method
  • MSTEST0029 - Public method should be test method
  • MSTEST0030 - Type containing test method should be a test class
  • MSTEST0036 - Do not use shadowing
  • MSTEST0041 - Use condition-based attributes with test class
  • MSTEST0044 - Prefer TestMethod over DataTestMethod
  • MSTEST0056 - TestMethodAttribute should set DisplayName correctly
  • MSTEST0057 - TestMethodAttribute should propagate source information
  • MSTEST0060 - Duplicate TestMethodAttribute
  • MSTEST0063 - Test class should have valid constructor

Related documentation: Write tests with MSTest, Attributes

Async/await patterns

Rules for writing asynchronous test code correctly:

  • MSTEST0013 - AssemblyCleanup should be valid (includes async rules)
  • MSTEST0027 - Suppress async suffix for test methods
  • MSTEST0028 - Suppress async suffix for test fixture methods
  • MSTEST0039 - Use newer Assert.Throws methods (async variants)
  • MSTEST0040 - Avoid using asserts in async void context
  • MSTEST0045 - Use cooperative cancellation for timeout
  • MSTEST0049 - Flow TestContext CancellationToken
  • MSTEST0054 - Use CancellationToken property

Related documentation: TestContext

Data-driven testing

Rules for working with data-driven test scenarios:

Related documentation: Attributes used for data-driven testing

Lifecycle & initialization

Rules for test initialization, cleanup, and lifecycle management:

Related documentation: Lifecycle

Assertions

Rules for using assertion methods correctly and effectively:

Related documentation: Assertions

TestContext

Rules for properly using the TestContext object:

Related documentation: TestContext

Test configuration

Rules for configuring test execution, parallelization, and other test settings:

  • MSTEST0001 - Use Parallelize attribute
  • MSTEST0015 - Test method should not be ignored
  • MSTEST0031 - Do not use System.ComponentModel.DescriptionAttribute
  • MSTEST0035 - Use DeploymentItem with test method or test class
  • MSTEST0043 - Use retry attribute on test method
  • MSTEST0045 - Use cooperative cancellation for timeout
  • MSTEST0055 - Do not ignore string method return value
  • MSTEST0059 - Use Parallelize attribute correctly
  • MSTEST0061 - Use OSCondition attribute instead of runtime check

Related documentation: Configure MSTest, Running tests

All rules (quick reference)

Rule ID Category Title Default Severity
MSTEST0001 Performance Use Parallelize attribute Info
MSTEST0002 Usage Test class should be valid Warning
MSTEST0003 Usage Test method should be valid Warning → Error*
MSTEST0004 Design Public types should be test classes Info
MSTEST0005 Usage TestContext should be valid Warning
MSTEST0006 Design Avoid ExpectedException attribute Info
MSTEST0007 Usage Use attribute on test method Warning
MSTEST0008 Usage TestInitialize should be valid Warning
MSTEST0009 Usage TestCleanup should be valid Warning
MSTEST0010 Usage ClassInitialize should be valid Warning
MSTEST0011 Usage ClassCleanup should be valid Warning
MSTEST0012 Usage AssemblyInitialize should be valid Warning
MSTEST0013 Usage AssemblyCleanup should be valid Warning
MSTEST0014 Usage DataRow should be valid Warning
MSTEST0015 Design Test method should not be ignored None (opt-in)
MSTEST0016 Design Test class should have test method Info
MSTEST0017 Usage Assertion args should be passed in correct order Info
MSTEST0018 Usage DynamicData should be valid Warning
MSTEST0019 Design Prefer TestInitialize over constructors None (opt-in)
MSTEST0020 Design Prefer constructors over TestInitialize None (opt-in)
MSTEST0021 Design Prefer Dispose over TestCleanup None (opt-in)
MSTEST0022 Design Prefer TestCleanup over Dispose None (opt-in)
MSTEST0023 Usage Do not negate boolean assertion Info
MSTEST0024 Usage Do not store static TestContext Warning
MSTEST0025 Design Prefer Assert.Fail over always-false conditions Info
MSTEST0026 Usage Assertion args should avoid conditional access Info
MSTEST0027 Suppression Suppress async suffix for test methods N/A
MSTEST0028 Suppression Suppress async suffix for test fixture methods N/A
MSTEST0029 Design Public method should be test method Info
MSTEST0030 Usage Type containing test method should be a test class Warning
MSTEST0031 Usage Do not use System.ComponentModel.DescriptionAttribute Info
MSTEST0032 Usage Review always-true assert condition Info
MSTEST0033 Suppression Suppress non-nullable reference not initialized N/A
MSTEST0034 Usage Use ClassCleanupBehavior.EndOfClass Info
MSTEST0035 Usage Use DeploymentItem with test method or test class Info
MSTEST0036 Design Do not use shadowing Warning
MSTEST0037 Usage Use proper assert methods Info
MSTEST0038 Usage Avoid Assert.AreSame with value types Info
MSTEST0039 Usage Use newer Assert.Throws methods Info
MSTEST0040 Usage Avoid using asserts in async void context Warning
MSTEST0041 Usage Use condition-based attributes with test class Warning
MSTEST0042 Usage Duplicate DataRow Warning
MSTEST0043 Usage Use retry attribute on test method Warning → Error*
MSTEST0044 Design Prefer TestMethod over DataTestMethod Info
MSTEST0045 Design Use cooperative cancellation for timeout Info
MSTEST0046 Usage Use Assert instead of StringAssert Info
MSTEST0048 Usage TestContext property usage Warning
MSTEST0049 Usage Flow TestContext CancellationToken Info
MSTEST0050 Usage Global test fixture should be valid Warning
MSTEST0051 Usage Assert.Throws should contain single statement Info
MSTEST0052 Usage Avoid explicit DynamicDataSourceType Info
MSTEST0053 Usage Avoid Assert format parameters Info
MSTEST0054 Usage Use CancellationToken property Info
MSTEST0055 Usage Do not ignore string method return value Warning
MSTEST0056 Usage TestMethodAttribute should set DisplayName correctly Info
MSTEST0057 Usage TestMethodAttribute should propagate source information Warning
MSTEST0058 Usage Avoid asserts in catch blocks Info
MSTEST0059 Usage Use Parallelize attribute correctly Warning
MSTEST0060 Usage Duplicate TestMethodAttribute Warning
MSTEST0061 Usage Use OSCondition attribute instead of runtime check Info
MSTEST0062 Usage Avoid out/ref test method parameters Warning
MSTEST0063 Usage Test class should have valid constructor Warning

* Escalated to Error in Recommended and All modes.

MSTESTEXP

Several APIs of MSTest are decorated with the ExperimentalAttribute. This attribute indicates that the API is experimental and may be removed or changed in future versions of MSTest. The attribute is used to identify APIs that aren't yet stable and may not be suitable for production use.

The MSTESTEXP diagnostic alerts you to use of an experimental API in your code. To suppress this diagnostic with the SuppressMessageAttribute, add the following code to your project:

using System.Diagnostics.CodeAnalysis;

[assembly: SuppressMessage("MSTESTEXP", "Justification")]

Alternatively, you can suppress this diagnostic with preprocessor directive by adding the following code to your project:

#pragma warning disable MSTESTEXP
        // API that is causing the warning.
#pragma warning restore MSTESTEXP
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