.NET Test Runner

Run .NET tests selectively using a build-first, test-targeted workflow optimized for development speed.

Core Workflow

Follow this workflow to run tests efficiently:

Step 1: Build Solution First

Build the entire solution with minimal output to catch compile errors early:

dotnet build -p:WarningLevel=0 /clp:ErrorsOnly --verbosity minimal

Step 2: Run Specific Project Tests

Run tests for the specific test project with --no-build to skip redundant compilation:

dotnet test path/to/project --no-build --verbosity minimal

Step 3: Filter When Targeting Specific Tests

Narrow down to specific tests using filter expressions:

By method name using FullyQualifiedName (recommended)

dotnet test --no-build --filter "FullyQualifiedName~MyTestMethod"

By class name using FullyQualifiedName (recommended)

dotnet test --no-build --filter "FullyQualifiedName~MyTestClass"

By parameter values in Theory tests (xUnit)

dotnet test --no-build --filter "DisplayName~paramValue"

Combined filters

dotnet test --no-build --filter "FullyQualifiedNameCreate|FullyQualifiedNameUpdate"

Note: Properties Name~ and ClassName= may not work reliably. Use FullyQualifiedName~ instead.

Quick Reference

Commands

Command Purpose

dotnet build -p:WarningLevel=0 /clp:ErrorsOnly --verbosity minimal

Build solution with minimal output

dotnet test path/to/Tests.csproj --no-build

Run project tests (skip build)

dotnet test --no-build --logger "console;verbosity=detailed"

Show ITestOutputHelper output

dotnet test --no-build --filter "..."

Run filtered tests

dotnet test --no-build --list-tests

List available tests without running

Filter Operators

Operator Meaning Example

=

Exact match ClassName=MyTests

!=

Not equal Name!=SkipThis

~

Contains Name~Create

!~

Does not contain Name!~Integration

|

OR NameTest1|NameTest2 (note '|' is an escape for markdown)

&

AND Name~User&Category=Unit

xUnit Filter Properties

Property Description Reliability Example

FullyQualifiedName

Full test name with namespace ✅ Reliable FullyQualifiedName~MyNamespace.MyClass

DisplayName

Test display name (includes Theory parameters) ✅ Reliable DisplayNameMy_Test_Name or DisplayNameparamValue

Name

Method name ⚠️ Unreliable Use FullyQualifiedName~ instead

ClassName

Class name ⚠️ Unreliable Use FullyQualifiedName~ instead

Category

Trait category ✅ Reliable Category=Unit

When to use DisplayName: Essential for filtering Theory tests by their parameter values. xUnit includes all parameter values in the DisplayName (e.g., MyTest(username: "admin", age: 30) ), making it ideal for running specific test cases. See references/theory-parameter-filtering.md for detailed guidance.

Common Filter Patterns

Run tests containing "Create" in method name

dotnet test --no-build --filter "FullyQualifiedName~Create"

Run tests in a specific class

dotnet test --no-build --filter "FullyQualifiedName~UserServiceTests"

Run tests matching namespace pattern

dotnet test --no-build --filter "FullyQualifiedName~MyApp.Tests.Unit"

Run Theory tests with specific parameter value

dotnet test --no-build --filter "DisplayName~admin_user"

Run tests with specific trait

dotnet test --no-build --filter "Category=Integration"

Exclude slow tests

dotnet test --no-build --filter "Category!=Slow"

Combined: class AND parameter value (Theory tests)

dotnet test --no-build --filter "FullyQualifiedNameOrderTests&DisplayNameUSD"

Multiple parameter values (OR condition)

dotnet test --no-build --filter "DisplayNameEUR|DisplayNameGBP"

ITestOutputHelper Output

To see output from xUnit's ITestOutputHelper , use the console logger with detailed verbosity:

dotnet test --no-build --logger "console;verbosity=detailed"

Reducing Output Noise

Verbosity levels for dotnet test :

Level Flag Description

quiet -v q

Minimal output (pass/fail only)

minimal -v m

Clean summary, no test output

normal -v n

Default, shows discovered tests

detailed -v d

Shows more details

diagnostic -v diag

Most verbose

To see test output, use grep to filter out discovery messages (for xUnit):

dotnet test --no-build --logger "console;verbosity=detailed" 2>&1 | grep -v "Discovered [execution]"

Framework Differences

This skill focuses on xUnit. For MSTest or NUnit, filter property names differ:

Property xUnit MSTest NUnit

Method name Name

Name

Name

Class name ClassName

ClassName

ClassName

Category/Trait Category

TestCategory

Category

Priority

Priority

Priority

Progressive Disclosure

For advanced scenarios, load additional references:

• references/theory-parameter-filtering.md - Filtering xUnit Theory tests by parameter values (string, numeric, boolean, etc.)

• references/blame-mode.md - Debugging test crashes and hangs with --blame

• references/parallel-execution.md - Controlling parallel test execution

Load these references when:

• Working with xUnit Theory tests and need to filter by specific parameter values

• Tests are crashing or hanging unexpectedly

• Diagnosing test isolation issues

• Optimizing test run performance

When to Use This Skill

Invoke when the user needs to:

• Run targeted tests during development

• Filter tests by method or class name

• Filter xUnit Theory tests by specific parameter values (e.g., run only admin user test cases)

• Understand test output and filtering options

• Debug failing or hanging tests