dotnet-ado-build-test

.NET build and test pipeline patterns for Azure DevOps: DotNetCoreCLI@2 task for build, test, and pack operations, NuGet restore with Azure Artifacts feeds using NuGetAuthenticate@1 , test result publishing with PublishTestResults@2 for TRX and JUnit formats, code coverage with PublishCodeCoverageResults@2 for Cobertura and JaCoCo formats, and multi-TFM matrix strategy across net8.0 and net9.0.

Version assumptions: DotNetCoreCLI@2 task (current). UseDotNet@2 for SDK installation. NuGetAuthenticate@1 for Azure Artifacts. PublishTestResults@2 and PublishCodeCoverageResults@2 for reporting.

Scope

• DotNetCoreCLI@2 task for build, test, pack, and custom commands

• NuGet restore with Azure Artifacts feeds (NuGetAuthenticate@1)

• Test result publishing with PublishTestResults@2 (TRX, JUnit)

• Code coverage with PublishCodeCoverageResults@2 (Cobertura)

• Multi-TFM matrix strategy across TFMs and operating systems

Out of scope

• Starter CI templates -- see [skill:dotnet-add-ci]

• Test architecture and strategy -- see [skill:dotnet-testing-strategy]

• Benchmark regression detection in CI -- see [skill:dotnet-ci-benchmarking]

• Publishing and deployment -- see [skill:dotnet-ado-publish] and [skill:dotnet-ado-unique]

• GitHub Actions build/test workflows -- see [skill:dotnet-gha-build-test]

Cross-references: [skill:dotnet-add-ci] for starter build/test templates, [skill:dotnet-testing-strategy] for test architecture guidance, [skill:dotnet-ci-benchmarking] for benchmark CI integration.

DotNetCoreCLI@2 Task

Build

steps:

• task: UseDotNet@2 displayName: 'Install .NET SDK' inputs: packageType: 'sdk' version: '8.0.x'

• task: DotNetCoreCLI@2 displayName: 'Restore' inputs: command: 'restore' projects: 'MyApp.sln'

• task: DotNetCoreCLI@2 displayName: 'Build' inputs: command: 'build' projects: 'MyApp.sln' arguments: '-c Release --no-restore'

Test

• task: DotNetCoreCLI@2 displayName: 'Run tests' inputs: command: 'test' projects: '**/*Tests.csproj' arguments: >- -c Release --logger "trx;LogFileName=test-results.trx" --results-directory $(Build.ArtifactStagingDirectory)/test-results

Pack

• task: DotNetCoreCLI@2 displayName: 'Pack NuGet packages' inputs: command: 'pack' packagesToPack: 'src/**/*.csproj' configuration: 'Release' outputDir: '$(Build.ArtifactStagingDirectory)/nupkgs' nobuild: true

Custom Command

For commands not directly supported by the task (e.g., dotnet tool install ):

• task: DotNetCoreCLI@2 displayName: 'Install dotnet tools' inputs: command: 'custom' custom: 'tool' arguments: 'restore'

Multi-Version SDK Install

Install multiple SDK versions for multi-TFM builds:

• task: UseDotNet@2 displayName: 'Install .NET 8' inputs: packageType: 'sdk' version: '8.0.x'

• task: UseDotNet@2 displayName: 'Install .NET 9' inputs: packageType: 'sdk' version: '9.0.x'

Each UseDotNet@2 invocation adds the SDK version to PATH. The last installed version becomes the default, but all versions are available via --framework targeting.

NuGet Restore with Azure Artifacts Feeds

NuGetAuthenticate@1 for Feed Authentication

steps:

• task: NuGetAuthenticate@1 displayName: 'Authenticate NuGet feeds'

• task: DotNetCoreCLI@2 displayName: 'Restore' inputs: command: 'restore' projects: 'MyApp.sln' feedsToUse: 'config' nugetConfigPath: 'nuget.config'

The NuGetAuthenticate@1 task configures credentials for all Azure Artifacts feeds referenced in nuget.config . No explicit PAT or API key is needed -- the task uses the pipeline's identity.

Selecting Feeds Directly

For simple setups without a nuget.config , select feeds directly in the restore task:

• task: DotNetCoreCLI@2 displayName: 'Restore with Azure Artifacts' inputs: command: 'restore' projects: 'MyApp.sln' feedsToUse: 'select' vstsFeed: 'MyProject/MyFeed' includeNuGetOrg: true

Upstream Sources

Azure Artifacts feeds can proxy nuget.org as an upstream source. When configured, a single feed reference provides access to both private packages and public NuGet packages:

<!-- nuget.config with Azure Artifacts upstream --> <?xml version="1.0" encoding="utf-8"?> <configuration> <packageSources> <clear /> <add key="MyFeed" value="https://pkgs.dev.azure.com/myorg/_packaging/myfeed/nuget/v3/index.json" /> </packageSources> </configuration>

With upstream sources enabled on the feed, nuget.org packages are cached in the Azure Artifacts feed, providing a single authenticated source for all packages.

Cross-Organization Feed Access

For feeds in different Azure DevOps organizations, use a service connection:

• task: NuGetAuthenticate@1 displayName: 'Authenticate external feed' inputs: nuGetServiceConnections: 'ExternalOrgFeedConnection'

• task: DotNetCoreCLI@2 displayName: 'Restore' inputs: command: 'restore' projects: 'MyApp.sln' feedsToUse: 'config' nugetConfigPath: 'nuget.config'

Test Result Publishing

PublishTestResults@2 with TRX Format

• task: DotNetCoreCLI@2 displayName: 'Run tests' inputs: command: 'test' projects: '**/*Tests.csproj' arguments: >- -c Release --logger "trx;LogFileName=results.trx" --results-directory $(Common.TestResultsDirectory) continueOnError: true

• task: PublishTestResults@2 displayName: 'Publish test results' condition: always() inputs: testResultsFormat: 'VSTest' testResultsFiles: '$(Common.TestResultsDirectory)/**/*.trx' mergeTestResults: true testRunTitle: '.NET Unit Tests'

Key decisions:

• continueOnError: true on the test task ensures the publish step always runs, even on test failures

• condition: always() on the publish task runs regardless of previous step outcome

• mergeTestResults: true combines results from multiple test projects into a single test run

• testRunTitle provides a descriptive name in the Azure DevOps Test tab

JUnit Format

Some third-party test frameworks output JUnit XML. Use the JUnit format:

• task: PublishTestResults@2 displayName: 'Publish JUnit results' condition: always() inputs: testResultsFormat: 'JUnit' testResultsFiles: '**/junit-results.xml' mergeTestResults: true

Test Results with Attachments

Attach screenshots or logs to test results for debugging failed tests:

• task: DotNetCoreCLI@2 displayName: 'Run tests with attachments' inputs: command: 'test' projects: '**/*Tests.csproj' arguments: >- -c Release --logger "trx;LogFileName=results.trx" --results-directory $(Common.TestResultsDirectory) --collect:"XPlat Code Coverage" continueOnError: true

• task: PublishTestResults@2 displayName: 'Publish test results' condition: always() inputs: testResultsFormat: 'VSTest' testResultsFiles: '$(Common.TestResultsDirectory)/**/*.trx' mergeTestResults: true testRunTitle: '.NET Tests' publishRunAttachments: true

Code Coverage

PublishCodeCoverageResults@2 with Cobertura

• task: DotNetCoreCLI@2 displayName: 'Test with coverage' inputs: command: 'test' projects: '**/*Tests.csproj' arguments: >- -c Release --collect:"XPlat Code Coverage" --results-directory $(Agent.TempDirectory)/coverage

• task: PublishCodeCoverageResults@2 displayName: 'Publish code coverage' inputs: summaryFileLocation: '$(Agent.TempDirectory)/coverage/**/coverage.cobertura.xml'

The PublishCodeCoverageResults@2 task (v2) auto-generates HTML coverage reports in the Azure DevOps Build Summary tab without requiring reportgenerator .

Coverage with ReportGenerator for Detailed Reports

For custom coverage reports beyond the built-in rendering:

• task: DotNetCoreCLI@2 displayName: 'Test with coverage' inputs: command: 'test' projects: '**/*Tests.csproj' arguments: >- -c Release --collect:"XPlat Code Coverage" --results-directory $(Agent.TempDirectory)/coverage

• script: | set -euo pipefail dotnet tool install -g dotnet-reportgenerator-globaltool reportgenerator
  -reports:$(Agent.TempDirectory)/coverage/**/coverage.cobertura.xml
  -targetdir:$(Build.ArtifactStagingDirectory)/coverage-report
  -reporttypes:HtmlInline_AzurePipelines;Cobertura displayName: 'Generate coverage report'

• task: PublishCodeCoverageResults@2 displayName: 'Publish coverage' inputs: summaryFileLocation: '$(Build.ArtifactStagingDirectory)/coverage-report/Cobertura.xml'

• task: PublishPipelineArtifact@1 displayName: 'Upload coverage report' inputs: targetPath: '$(Build.ArtifactStagingDirectory)/coverage-report' artifactName: 'coverage-report'

Coverage Thresholds

Enforce minimum coverage by parsing the Cobertura XML in a script step:

• script: | set -euo pipefail COVERAGE_FILE=$(find $(Agent.TempDirectory)/coverage -name 'coverage.cobertura.xml' | head -1) COVERAGE=$(python3 -c " import xml.etree.ElementTree as ET tree = ET.parse('$COVERAGE_FILE') print(float(tree.getroot().attrib['line-rate']) * 100) ") echo "Line coverage: ${COVERAGE}%" if (( $(echo "$COVERAGE < 80" | bc -l) )); then echo "##vso[task.logissue type=error]Coverage ${COVERAGE}% is below 80% threshold" exit 1 fi displayName: 'Enforce coverage threshold'

Multi-TFM Matrix Strategy

Matrix Build Across TFMs and Operating Systems

jobs:

• job: Test strategy: matrix: Linux_net80: vmImage: 'ubuntu-latest' tfm: 'net8.0' dotnetVersion: '8.0.x' Linux_net90: vmImage: 'ubuntu-latest' tfm: 'net9.0' dotnetVersion: '9.0.x' Windows_net80: vmImage: 'windows-latest' tfm: 'net8.0' dotnetVersion: '8.0.x' Windows_net90: vmImage: 'windows-latest' tfm: 'net9.0' dotnetVersion: '9.0.x' pool: vmImage: $(vmImage) steps:

  • task: UseDotNet@2 displayName: 'Install .NET $(dotnetVersion)' inputs: packageType: 'sdk' version: $(dotnetVersion)

  • task: DotNetCoreCLI@2 displayName: 'Test $(tfm) on $(vmImage)' inputs: command: 'test' projects: '**/*Tests.csproj' arguments: >- -c Release --framework $(tfm) --logger "trx;LogFileName=$(tfm)-results.trx" --results-directory $(Common.TestResultsDirectory) continueOnError: true

  • task: PublishTestResults@2 displayName: 'Publish $(tfm) results' condition: always() inputs: testResultsFormat: 'VSTest' testResultsFiles: '$(Common.TestResultsDirectory)/**/*.trx' testRunTitle: '$(tfm) on $(vmImage)'

Installing Multiple SDKs for Multi-TFM in a Single Job

When running all TFMs in one job (instead of matrix), install all required SDKs:

steps:

• task: UseDotNet@2 displayName: 'Install .NET 8' inputs: packageType: 'sdk' version: '8.0.x'

• task: UseDotNet@2 displayName: 'Install .NET 9' inputs: packageType: 'sdk' version: '9.0.x'

• task: DotNetCoreCLI@2 displayName: 'Test all TFMs' inputs: command: 'test' projects: '**/*Tests.csproj' arguments: '-c Release'

Without the matching SDK installed, dotnet test cannot build for that TFM and fails with NETSDK1045 .

Template-Based Matrix for Reusability

templates/jobs/matrix-test.yml

parameters:

• name: configurations type: object default:
  • tfm: 'net8.0' dotnetVersion: '8.0.x'
  • tfm: 'net9.0' dotnetVersion: '9.0.x'

jobs:

• ${{ each config in parameters.configurations }}:
  • job: Test_${{ replace(config.tfm, '.', '_') }} displayName: 'Test ${{ config.tfm }}' pool: vmImage: 'ubuntu-latest' steps:

    • task: UseDotNet@2 inputs: packageType: 'sdk' version: ${{ config.dotnetVersion }}

    • task: DotNetCoreCLI@2 displayName: 'Test ${{ config.tfm }}' inputs: command: 'test' projects: '**/*Tests.csproj' arguments: '-c Release --framework ${{ config.tfm }}'

Agent Gotchas

• Use set -euo pipefail in multi-line script: steps -- ADO script: tasks on Linux default to set -e but do not set pipefail or nounset ; without pipefail , a failure in a piped command is silently swallowed.

• Use continueOnError: true on the test task, not on the result publisher -- the test task must not fail the pipeline before results are published, but the publisher should reflect the actual test outcome.

• Install all required SDK versions for multi-TFM builds -- dotnet test without the matching SDK produces NETSDK1045 ; add a UseDotNet@2 step for each required version.

• NuGetAuthenticate@1 must precede the restore step -- authentication tokens are injected into the agent's NuGet config at task execution time; restoring before authentication fails with 401.

• Use feedsToUse: 'config' with nuget.config for complex feed setups -- feedsToUse: 'select' supports only one Azure Artifacts feed; multi-feed scenarios require a nuget.config file.

• Coverage collection requires --collect:"XPlat Code Coverage" -- the default dotnet test does not produce coverage files; the XPlat Code Coverage collector is built into the .NET SDK.

• PublishCodeCoverageResults@2 expects Cobertura XML -- passing TRX or other formats to the coverage publisher produces no output; ensure the collector outputs Cobertura format.

• ADO matrix syntax differs from GHA -- ADO uses named matrix entries with key-value pairs, not arrays; each entry must define all variable names used in the job.

• Never hardcode credentials in pipeline YAML -- use variable groups linked to Azure Key Vault or pipeline-level secret variables; hardcoded secrets are visible in repository history.