filter-syntax skill

Test Filter Syntax Reference

Filter syntax depends on the platform and test framework.

VSTest filters (MSTest, xUnit v2, NUnit on VSTest)

dotnet test --filter <EXPRESSION>

Expression syntax: <Property><Operator><Value>[|&<Expression>]

Operators:

Operator	Meaning
=	Exact match
!=	Not exact match
~	Contains
!~	Does not contain

Combinators: | (OR), & (AND). Parentheses for grouping: (A|B)&C

Supported properties by framework:

Framework	Properties
MSTest	FullyQualifiedName, Name, ClassName, Priority, TestCategory
xUnit	FullyQualifiedName, DisplayName, Traits
NUnit	FullyQualifiedName, Name, Priority, TestCategory

An expression without an operator is treated as FullyQualifiedName~<value>.

Examples (VSTest):

# Run tests whose name contains "LoginTest"
dotnet test --filter "Name~LoginTest"

# Run a specific test class
dotnet test --filter "ClassName=MyNamespace.MyTestClass"

# Run tests in a category
dotnet test --filter "TestCategory=Integration"

# Exclude a category
dotnet test --filter "TestCategory!=Slow"

# Combine: class AND category
dotnet test --filter "ClassName=MyNamespace.MyTestClass&TestCategory=Unit"

# Either of two classes
dotnet test --filter "ClassName=MyNamespace.ClassA|ClassName=MyNamespace.ClassB"

MTP filters — MSTest and NUnit

MSTest and NUnit on MTP use the same --filter syntax as VSTest (same properties, operators, and combinators). The only difference is how the flag is passed:

# .NET SDK 8/9 (after --)
dotnet test -- --filter "Name~LoginTest"

# .NET SDK 10+ (direct)
dotnet test --filter "Name~LoginTest"

MTP filters — xUnit (v3)

xUnit v3 on MTP uses framework-specific filter flags instead of the generic --filter expression:

Flag	Description
--filter-class "name"	Run all tests in a given class
--filter-not-class "name"	Exclude all tests in a given class
--filter-method "name"	Run a specific test method
--filter-not-method "name"	Exclude a specific test method
--filter-namespace "name"	Run all tests in a namespace
--filter-not-namespace "name"	Exclude all tests in a namespace
--filter-trait "name=value"	Run tests with a matching trait
--filter-not-trait "name=value"	Exclude tests with a matching trait

Multiple values can be specified with a single flag: --filter-class Foo Bar.

# .NET SDK 8/9
dotnet test -- --filter-class "MyNamespace.LoginTests"

# .NET SDK 10+
dotnet test --filter-class "MyNamespace.LoginTests"

# Combine: namespace + trait
dotnet test --filter-namespace "MyApp.Tests.Integration" --filter-trait "Category=Smoke"

xUnit v3 query filter language

For complex expressions, use --filter-query with a path-segment syntax:

/<assemblyFilter>/<namespaceFilter>/<classFilter>/<methodFilter>[traitName=traitValue]

Each segment matches against: assembly name, namespace, class name, method name. Use * for "match all" in any segment. Documentation: https://xunit.net/docs/query-filter-language

# xUnit.net v3 MTP — using query language (assembly/namespace/class/method[trait])
dotnet test -- --filter-query "/*/*/*IntegrationTests*/*[Category=Smoke]"

MTP filters — TUnit

TUnit uses --treenode-filter with a path-based syntax:

--treenode-filter "/<Assembly>/<Namespace>/<ClassName>/<TestName>"

Wildcards (*) are supported in any segment. Filter operators can be appended to test names for property-based filtering.

Operator	Meaning
*	Wildcard match
=	Exact property match (e.g., [Category=Unit])
!=	Exclude property value
&	AND (combine conditions)
|	OR (within a segment, requires parentheses)

Examples (TUnit):

# All tests in a class
dotnet run --treenode-filter "/*/*/LoginTests/*"

# A specific test
dotnet run --treenode-filter "/*/*/*/AcceptCookiesTest"

# By namespace prefix (wildcard)
dotnet run --treenode-filter "/*/MyProject.Tests.Api*/*/*"

# By custom property
dotnet run --treenode-filter "/*/*/*/*[Category=Smoke]"

# Exclude by property
dotnet run --treenode-filter "/*/*/*/*[Category!=Slow]"

# OR across classes
dotnet run --treenode-filter "/*/*/(LoginTests)|(SignupTests)/*"

# Combined: namespace + property
dotnet run --treenode-filter "/*/MyProject.Tests.Integration/*/*/*[Priority=Critical]"

VSTest → MTP filter translation (for migration)

MSTest, NUnit, and xUnit.net v2 (with YTest.MTP.XUnit2): The VSTest --filter syntax is identical on both VSTest and MTP. No changes needed.

xUnit.net v3 (native MTP): xUnit.net v3 does NOT support the VSTest --filter syntax on MTP. Translate filters using xUnit.net v3's native options:

VSTest --filter syntax	xUnit.net v3 MTP equivalent	Notes
FullyQualifiedName~ClassName	--filter-class *ClassName*	Wildcards required for substring match
FullyQualifiedName=Ns.Class.Method	--filter-method Ns.Class.Method	Exact match on fully qualified method
Name=MethodName	--filter-method *MethodName*	Wildcards for substring match
Category=Value (trait)	--filter-trait "Category=Value"	Filter by trait name/value pair
Complex expressions	--filter-query "expr"	Uses xUnit.net query filter language (see above)