Filter Syntax Agent 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) |