Filter Syntax

by dotnet0608d8924cd3MIT5.5K starsListed Oct 8, 2026Updated Oct 8, 2026Repository updated today

Reference-only filter syntax for VSTest and MTP with MSTest, NUnit, xUnit v3, and TUnit. Load only after the platform/framework is known and a consumer needs to create or translate a filter. Do not load for unfiltered runs or platform detection. Used by run-tests and mtp-hot-reload; never invoke directly.

Instructions onlySoftware Development
AI-generated overview

Reference for VSTest and MTP test filter syntax across MSTest, NUnit, xUnit v3 and TUnit.

What it does
This skill is a reference document describing how to write test filter expressions for VSTest and Microsoft Testing Platform (MTP). It lists operators, combinators and supported properties per framework, gives command examples, and provides a translation table from VSTest filters to xUnit v3 MTP equivalents. It produces guidance only, not runnable artifacts.
When to use it
Use it when the test platform and framework are already known and a filter must be created or translated, such as during migration from VSTest to MTP. It is not intended for unfiltered test runs or platform detection.
Requirements
No scripts or tools; it is an instructions-only reference. It assumes familiarity with dotnet test and the relevant test frameworks.

Test Filter Syntax Reference

Filter syntax depends on the platform and test framework.

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

bash
dotnet test --filter <EXPRESSION>

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

Operators:

OperatorMeaning
=Exact match
!=Not exact match
~Contains
!~Does not contain

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

Supported properties by framework:

FrameworkProperties
MSTestFullyQualifiedName, Name, ClassName, Priority, TestCategory
xUnitFullyQualifiedName, DisplayName, Traits
NUnitFullyQualifiedName, Name, Priority, TestCategory

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

Examples (VSTest):

bash
# Run tests whose name contains "LoginTest"dotnet test --filter "Name~LoginTest"
# Run a specific test classdotnet test --filter "ClassName=MyNamespace.MyTestClass"
# Run tests in a categorydotnet test --filter "TestCategory=Integration"
# Exclude a categorydotnet test --filter "TestCategory!=Slow"
# Combine: class AND categorydotnet test --filter "ClassName=MyNamespace.MyTestClass&TestCategory=Unit"
# Either of two classesdotnet 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:

bash
# .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:

FlagDescription
--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.

bash
# .NET SDK 8/9dotnet test -- --filter-class "MyNamespace.LoginTests"
# .NET SDK 10+dotnet test --filter-class "MyNamespace.LoginTests"
# Combine: namespace + traitdotnet 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:

text
/<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

shell
# 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:

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

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

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

Examples (TUnit):

bash
# All tests in a classdotnet run --treenode-filter "/*/*/LoginTests/*"
# A specific testdotnet run --treenode-filter "/*/*/*/AcceptCookiesTest"
# By namespace prefix (wildcard)dotnet run --treenode-filter "/*/MyProject.Tests.Api*/*/*"
# By custom propertydotnet run --treenode-filter "/*/*/*/*[Category=Smoke]"
# Exclude by propertydotnet run --treenode-filter "/*/*/*/*[Category!=Slow]"
# OR across classesdotnet run --treenode-filter "/*/*/(LoginTests)|(SignupTests)/*"
# Combined: namespace + propertydotnet 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 syntaxxUnit.net v3 MTP equivalentNotes
FullyQualifiedName~ClassName--filter-class *ClassName*Wildcards required for substring match
FullyQualifiedName=Ns.Class.Method--filter-method Ns.Class.MethodExact 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)

Source and attribution

Source:dotnet/skillsinplugins/dotnet-test/skills/filter-syntaxat commit0608d89

License: MIT

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