.NET Test Execution

Basic Test Commands

Run all tests in solution

dotnet test

Run tests in specific project

dotnet test tests/MyApp.Tests/MyApp.Tests.csproj

Run without build (faster if already built)

dotnet test --no-build

Run without restore

dotnet test --no-restore

Test Filtering

By Name

Filter by fully qualified name (contains)

dotnet test --filter "FullyQualifiedName~OrderService"

Filter by test name (exact match)

dotnet test --filter "Name=CreateOrder_ValidInput_ReturnsOrder"

Filter by display name

dotnet test --filter "DisplayName~Create Order"

By Category/Trait

Filter by trait (xUnit)

dotnet test --filter "Category=Unit" dotnet test --filter "Category!=Integration"

Multiple trait filters

dotnet test --filter "Category=Unit&Priority=High" dotnet test --filter "Category=Unit|Category=Integration"

By Class/Namespace

Filter by class name

dotnet test --filter "ClassName=OrderServiceTests"

Filter by namespace

dotnet test --filter "FullyQualifiedName~MyApp.Tests.Services"

Complex Filters

Combine with operators

& (and), | (or), ! (not), ~ (contains), = (equals)

Unit tests except slow ones

dotnet test --filter "Category=Unit&Category!=Slow"

All tests in namespace containing "Order"

dotnet test --filter "FullyQualifiedName~Order&Category!=Integration"

Test Output

Verbosity Levels

Quiet (minimal output)

dotnet test --verbosity quiet dotnet test -v q

Normal (default)

dotnet test --verbosity normal

Detailed (shows all test names)

dotnet test --verbosity detailed dotnet test -v d

Diagnostic (maximum output)

dotnet test --verbosity diagnostic

Logger Options

Console logger with verbosity

dotnet test --logger "console;verbosity=detailed"

TRX (Visual Studio Test Results)

dotnet test --logger trx

JUnit format (for CI systems)

dotnet test --logger "junit;LogFileName=results.xml"

HTML report

dotnet test --logger "html;LogFileName=results.html"

Multiple loggers

dotnet test --logger trx --logger "console;verbosity=detailed"

Results Directory

Specify results output directory

dotnet test --results-directory ./TestResults

Code Coverage

Collect Coverage

Basic coverage collection

dotnet test --collect:"XPlat Code Coverage"

With Coverlet

dotnet test /p:CollectCoverage=true

Coverlet with specific format

dotnet test /p:CollectCoverage=true /p:CoverletOutputFormat=cobertura

Multiple formats

dotnet test /p:CollectCoverage=true /p:CoverletOutputFormat="opencover,cobertura"

Coverage Thresholds

Fail if coverage below threshold

dotnet test /p:CollectCoverage=true /p:Threshold=80

Per-type thresholds

dotnet test /p:CollectCoverage=true /p:ThresholdType=line /p:Threshold=80

Coverage Reports

Install report generator

dotnet tool install -g dotnet-reportgenerator-globaltool

Generate HTML report

reportgenerator -reports:coverage.cobertura.xml -targetdir:coveragereport

Parallel Execution

Control parallelism

dotnet test --parallel

Limit parallel workers

dotnet test -- RunConfiguration.MaxCpuCount=4

Disable parallel execution

dotnet test -- RunConfiguration.DisableParallelization=true

Test Timeouts

Set test timeout (milliseconds)

dotnet test -- RunConfiguration.TestSessionTimeout=60000

// Per-test timeout (xUnit) [Fact(Timeout = 5000)] public void SlowTest() { }

// Per-test timeout (NUnit) [Test, Timeout(5000)] public void SlowTest() { }

Configuration Files

runsettings

<?xml version="1.0" encoding="utf-8"?> <RunSettings> <RunConfiguration> <MaxCpuCount>4</MaxCpuCount> <ResultsDirectory>./TestResults</ResultsDirectory> <TestSessionTimeout>600000</TestSessionTimeout> </RunConfiguration> <DataCollectionRunSettings> <DataCollectors> <DataCollector friendlyName="XPlat Code Coverage"> <Configuration> <Format>cobertura</Format> <Exclude>[].Migrations.*</Exclude> </Configuration> </DataCollector> </DataCollectors> </DataCollectionRunSettings> </RunSettings>

Use runsettings file

dotnet test --settings test.runsettings

Test Failure Analysis

Common Failure Patterns

Pattern Cause Fix

Assert.Equal failed Expected != Actual Check logic, verify test data

NullReferenceException Null not handled Add null checks, verify setup

TimeoutException Test too slow Optimize or increase timeout

ObjectDisposedException Using disposed object Fix lifetime management

InvalidOperationException Invalid state Check test setup/order

Debugging Failed Tests

Run single failing test with detailed output

dotnet test --filter "FullyQualifiedName~FailingTest" -v d

Enable blame mode to catch hangs

dotnet test --blame

Blame with hang detection

dotnet test --blame-hang --blame-hang-timeout 60s

Watch Mode

Run tests on file changes

dotnet watch test

Watch specific project

dotnet watch --project tests/MyApp.Tests test

Watch with filter

dotnet watch test --filter "Category=Unit"

CI/CD Integration

Exit Codes

Code Meaning

0 All tests passed

1 Tests failed

2 Command line error

CI Examples

Azure DevOps

task: DotNetCoreCLI@2 inputs: command: test arguments: '--configuration Release --logger trx'

GitHub Actions

run: dotnet test --configuration Release --logger "trx;LogFileName=test-results.trx"

See test-filtering.md for advanced filtering patterns.