Skills filter-syntax

Name: filter-syntax
Author: dotnet

Reference data for test filter syntax across all platform and framework combinations: VSTest --filter expressions, MTP filters for MSTest/NUnit/xUnit v3/TUnit, and VSTest-to-MTP filter translation. DO NOT USE directly — loaded by run-tests, mtp-hot-reload, and migrate-vstest-to-mtp when they need filter syntax.

install

source · Clone the upstream repo

git clone https://github.com/dotnet/skills

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/dotnet/skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/plugins/dotnet-test/skills/filter-syntax" ~/.claude/skills/dotnet-skills-filter-syntax && rm -rf "$T"

manifest: plugins/dotnet-test/skills/filter-syntax/SKILL.md

source content

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)