# Filter Syntax

Reference-only filter syntax for VSTest and MTP with MSTest, NUnit, xUnit v3, and TUnit.

- Repository: https://github.com/managedcode/dotnet-skills (500 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-10-29
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add managedcode/dotnet-skills --skill filter-syntax -g -a claude-code -y`
Codex: `npx skills add managedcode/dotnet-skills --skill filter-syntax -g -a codex -y`
Cursor: `npx skills add managedcode/dotnet-skills --skill filter-syntax -g -a cursor -y`
Gemini CLI: `npx skills add managedcode/dotnet-skills --skill filter-syntax -g -a gemini-cli -y`

## Description

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.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# 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:**

| 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):**

```bash
# 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:

```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:

The rest: https://github.com/managedcode/dotnet-skills/blob/HEAD/catalog/Testing/Official-DotNet-Test/skills/filter-syntax/SKILL.md