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Configure unit tests by using a .runsettings file

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Applies to: yesVisual Studio noVisual Studio for Mac

Note

This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here

Unit tests in Visual Studio can be configured by using a .runsettings file. For example, you can change the .NET version on which the tests are run, the directory for the test results, or the data that's collected during a test run. A common use of a .runsettings file is to customize code coverage analysis.

Run settings files can be used to configure tests that are run from the command line, from the IDE, or in a build workflow using Azure Test Plans or Team Foundation Server (TFS).

Run settings files are optional. If you don't require any special configuration, you don't need a .runsettings file.

Create a run settings file and customize it

  1. Add a run settings file to your solution. In Solution Explorer, on the shortcut menu of your solution, choose Add > New Item, and select XML File. Save the file with a name such as test.runsettings.

    Tip

    The file name doesn't matter, as long as you use the extension .runsettings.

  2. Add the content from Example *.runsettings file, and then customize it to your needs as described in the sections that follow.

  3. Specify the *.runsettings file that you want using one of the following methods:

  4. Run the unit tests to use the custom run settings.

If you want to turn the custom settings off and on in the IDE, deselect or select the file in the Test > Test Settings menu.

Test settings menu with custom settings file in Visual Studio 2017

Tip

You can create more than one .runsettings file in your solution and select one as the active test settings file as needed.

Specify a run settings file in the IDE

The methods available depend on your version of Visual Studio.

To specify a run settings file in the IDE, select Test > Test Settings > Select Test Settings File, and then select the .runsettings file.

Select test settings file menu in Visual Studio 2017

The file appears on the Test Settings menu, and you can select or deselect it. While selected, the run settings file applies whenever you select Analyze Code Coverage.

Specify a run settings file from the command line

To run tests from the command line, use vstest.console.exe, and specify the settings file by using the /Settings parameter.

  1. Open Developer Command Prompt for Visual Studio.

  2. Enter a command similar to:

    vstest.console.exe MyTestAssembly.dll /EnableCodeCoverage /Settings:CodeCoverage.runsettings

    or

    vstest.console.exe --settings:test.runsettings test.dll

For more information, see VSTest.Console.exe command-line options.

The *.runsettings file

The *.runsettings file is an XML file that contains different configuration elements within the RunSettings element. The sections that follow detail the different elements. For a complete sample, see Example *.runsettings file.

<?xml version="1.0" encoding="utf-8"?>
<RunSettings>
  <!-- configuration elements -->
</RunSettings>

Each of the configuration elements is optional because it has a default value.

RunConfiguration element

<RunConfiguration>
    <MaxCpuCount>1</MaxCpuCount>
    <ResultsDirectory>.\TestResults</ResultsDirectory>
    <TargetPlatform>x86</TargetPlatform>
    <TargetFrameworkVersion>net6.0</TargetFrameworkVersion>
    <TestAdaptersPaths>%SystemDrive%\Temp\foo;%SystemDrive%\Temp\bar</TestAdaptersPaths>
    <TestSessionTimeout>10000</TestSessionTimeout>
    <TreatNoTestsAsError>true</TreatNoTestsAsError>
</RunConfiguration>

The RunConfiguration element can include the following elements:

Node Default Values
MaxCpuCount 1 The option name is case sensitive and is easy to misspell as MaxCPUCount.

This setting controls the level of parallelism on process-level. Use 0 to enable the maximum process-level parallelism.

This setting determines the maximum number of test DLLs, or other test containers that can run in parallel. Each DLL will run in its own testhost process, and will be isolated on the process level from the tests in other test DLLs. This setting does not force tests in each test DLL to run in parallel. Controlling the parallel execution within a DLL (on the thread-level) is up to the test framework such as MSTest, XUnit or NUnit.

The default value is 1, meaning that only one testhost will run at the same time. A special value 0 allows as many testhosts as you have logical processors (e.g. 6, for a computer with 6 physical cores without multi-threading, or 12, for a computer with 6 physical cores with multi-threading).

The actual number of testhosts that will be started is determined by the amount of distinct DLLs in the run.
ResultsDirectory The directory where test results are placed. The path is relative to the directory that contains .runsettings file.
TargetFrameworkVersion net40 or netcoreapp1.0 Omit this whole tag to auto-detect.

This setting defines the framework version, or framework family to use to run tests.

Accepted values are any framework moniker such as net48, net472,net6.0, net5.0, netcoreapp3.1, uap10.0 or any valid full framework name such as.NETFramework,Version=v4.7.2 or .NETCoreApp,Version=v6.0.0. For backwards compatibility Framework35, Framework40, Framework45, FrameworkCore10, FrameworkUap10 are accepted, meaning (net35, net40, net45, netcoreapp1.0 and uap10.0 respectively). All the values are case-insensitive.

The provided value is used to determine the test runtime provider to be used. Every test runtime provider must respect the framework family to be used, but might not respect the exact framework version:

For .NET Framework 4.5.1 - 4.8 a testhost that was built with the specified exact version is used. For values outside of that range, .NET Framework 4.5.1 testhost is used.

For .NET, the actual version is determined by the test project's <TargetFramework> (or more precisely runtimeconfig.json).

For UWP, the test project application is a testhost by itself, and determines the actual version of UWP that is used.

Omit the TargetFrameworkVersion element from the .runsettings file to automatically determine the framework version from the built binaries.

When auto-detecting, all target frameworks will be unified into a single common framework. When a different version from the same target framework family is found, the newer version is chosen (e.g. net452, net472, net48 = net48).

For .NET Framework runner (in Visual Studio, or vstest.console.exe in Developer command line) the common target framework is to net40. For .NET runner (dotnet test + DLLs), the common target framework is set to netcoreapp1.0.
TargetPlatform x86 Omit this whole tag to auto-detect.

This setting defines the architecture to use to run tests. Possible values are x86, x64, ARM, ARM64, S390x.

When auto-detecting, the architecture for AnyCPU DLLs may differ based on the runner. For .NET Framework runner (in Visual Studio, or vstest.console.exe in Developer command line), the default is x86. For .NET runner (dotnet test), the default is the current process architecture.
TreatTestAdapterErrorsAsWarnings false false, true
TestAdaptersPaths One or more paths to the directory where the TestAdapters are located
TestSessionTimeout Allows users to terminate a test session when it exceeds a given timeout. Setting a timeout ensures that resources are well consumed and test sessions are constrained to a set time. The setting is available in Visual Studio 2017 version 15.5 and later.
DotnetHostPath Specify a custom path to dotnet host that is used to run the testhost. This is useful when you are building your own dotnet, for example when building the dotnet/runtime repository. Specifying this option will skip looking for testhost.exe, and will always use the testhost.dll.
TreatNoTestsAsError false true or false
Specify a Boolean value, which defines the exit code when no tests are discovered. If the value is true and no tests are discovered, a non-zero exit code is returned. Otherwise, zero is returned.

DataCollectors element (diagnostic data adapters)

The DataCollectors element specifies settings of diagnostic data adapters. Diagnostic data adapters gather additional information about the environment and the application under test. Each adapter has default settings, and you only have to provide settings if you don't want to use the defaults.

<DataCollectionRunSettings>
  <DataCollectors>
    <!-- data collectors -->
  </DataCollectors>
</DataCollectionRunSettings>

CodeCoverage data collector

The code coverage data collector creates a log of which parts of the application code have been exercised in the test. For detailed information about customizing the settings for code coverage, see Customize code coverage analysis.

<DataCollector friendlyName="Code Coverage" uri="datacollector://Microsoft/CodeCoverage/2.0" assemblyQualifiedName="Microsoft.VisualStudio.Coverage.DynamicCoverageDataCollector, Microsoft.VisualStudio.TraceCollector, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
  <Configuration>
    <CodeCoverage>
      <ModulePaths>
        <Exclude>
          <ModulePath>.*CPPUnitTestFramework.*</ModulePath>
        </Exclude>
      </ModulePaths>

      <UseVerifiableInstrumentation>True</UseVerifiableInstrumentation>
      <AllowLowIntegrityProcesses>True</AllowLowIntegrityProcesses>
      <CollectFromChildProcesses>True</CollectFromChildProcesses>
      <CollectAspDotNet>False</CollectAspDotNet>
    </CodeCoverage>
  </Configuration>
</DataCollector>

VideoRecorder data collector

The video data collector captures a screen recording when tests are run. This recording is useful for troubleshooting UI tests. The video data collector is available in Visual Studio 2017 version 15.5 and later. For an example of configuring this data collector, see the Example *.runsettings file.

To customize any other type of diagnostic data adapters, use a test settings file.

Blame data collector

This option can help you isolate a problematic test that causes a test host crash. Running the collector creates an output file (Sequence.xml) in TestResults, which captures the order of execution of the test before the crash.

<DataCollector friendlyName="blame" enabled="True">
</DataCollector>

TestRunParameters

<TestRunParameters>
    <Parameter name="webAppUrl" value="http://localhost" />
    <Parameter name="docsUrl" value="https://docs.microsoft.com" />
</TestRunParameters>

Test run parameters provide a way to define variables and values that are available to the tests at run time. Access the parameters using the MSTest TestContext.Properties property (or the NUnit TestContext):

private string _appUrl;
public TestContext TestContext { get; set; }

[TestMethod] // [Test] for NUnit
public void HomePageTest()
{
    string _appURL = TestContext.Properties["webAppUrl"];
}

To use test run parameters, add a public TestContext property to your test class.

LoggerRunSettings element

The LoggerRunSettings section defines one or more loggers to be used for the test run. The most common loggers are console, Visual Studio Test Results File (trx), and html.

<LoggerRunSettings>
    <Loggers>
      <Logger friendlyName="console" enabled="True">
        <Configuration>
            <Verbosity>quiet</Verbosity>
        </Configuration>
      </Logger>
      <Logger friendlyName="trx" enabled="True">
        <Configuration>
          <LogFileName>foo.trx</LogFileName>
        </Configuration>
      </Logger>
      <Logger friendlyName="html" enabled="True">
        <Configuration>
          <LogFileName>foo.html</LogFileName>
        </Configuration>
      </Logger>
    </Loggers>
  </LoggerRunSettings>

MSTest element

These settings are specific to the test adapter that runs test methods that have the TestMethodAttribute attribute.

<MSTest>
    <MapInconclusiveToFailed>True</MapInconclusiveToFailed>
    <CaptureTraceOutput>false</CaptureTraceOutput>
    <DeleteDeploymentDirectoryAfterTestRunIsComplete>False</DeleteDeploymentDirectoryAfterTestRunIsComplete>
    <DeploymentEnabled>False</DeploymentEnabled>
    <AssemblyResolution>
      <Directory path="D:\myfolder\bin\" includeSubDirectories="false"/>
    </AssemblyResolution>
</MSTest>
Configuration Default Values
ForcedLegacyMode false In Visual Studio 2012, the MSTest adapter was optimized to make it faster and more scalable. Some behavior, such as the order in which tests are run, might not be exactly as it was in previous editions of Visual Studio. Set this value to true to use the older test adapter.

For example, you might use this setting if you have an app.config file specified for a unit test.

We recommend that you consider refactoring your tests to allow you to use the newer adapter.
IgnoreTestImpact false The test impact feature prioritizes tests that are affected by recent changes, when run in MSTest or from Microsoft Test Manager (deprecated in Visual Studio 2017). This setting deactivates the feature. For more information, see Which tests should be run since a previous build.
SettingsFile You can specify a test settings file to use with the MSTest adapter here. You can also specify a test settings file from the settings menu.

If you specify this value, you must also set the ForcedLegacyMode to true.

<ForcedLegacyMode>true</ForcedLegacyMode>
KeepExecutorAliveAfterLegacyRun false After a test run is completed, MSTest is shut down. Any process that is launched as part of the test is also killed. If you want to keep the test executor alive, set the value to true. For example, you could use this setting to keep the browser running between coded UI tests.
DeploymentEnabled true If you set the value to false, deployment items that you've specified in your test method aren't copied to the deployment directory.
CaptureTraceOutput true You can write to the debug trace from your test method using Trace.WriteLine.
DeleteDeploymentDirectoryAfterTestRunIsComplete true To retain the deployment directory after a test run, set this value to false.
MapInconclusiveToFailed false If a test completes with an inconclusive status, it is mapped to the skipped status in Test Explorer. If you want inconclusive tests to be shown as failed, set the value to true.
InProcMode false If you want your tests to be run in the same process as the MSTest adapter, set this value to true. This setting provides a minor performance gain. But if a test exits with an exception, the remaining tests don't run.
AssemblyResolution false You can specify paths to additional assemblies when finding and running unit tests. For example, use these paths for dependency assemblies that aren't in the same directory as the test assembly. To specify a path, use a Directory Path element. Paths can include environment variables.

<AssemblyResolution> <Directory path="D:\myfolder\bin\" includeSubDirectories="false"/> </AssemblyResolution>

Example .runsettings file

The following XML shows the contents of a typical .runsettings file. Copy this code and edit it to suit your needs.

Each element of the file is optional because it has a default value.

<?xml version="1.0" encoding="utf-8"?>
<RunSettings>
  <!-- Configurations that affect the Test Framework -->
  <RunConfiguration>
    <!-- Use 0 for maximum process-level parallelization. This does not force parallelization within the test DLL (on the thread-level). You can also change it from the Test menu; choose "Run tests in parallel". Unchecked = 1 (only 1), checked = 0 (max). -->
    <MaxCpuCount>1</MaxCpuCount>
    <!-- Path relative to directory that contains .runsettings file-->
    <ResultsDirectory>.\TestResults</ResultsDirectory>

    <!-- Omit the whole tag for auto-detection. -->
    <!-- [x86] or x64, ARM, ARM64, s390x  -->
    <!-- You can also change it from the Test menu; choose "Processor Architecture for AnyCPU Projects" -->
    <TargetPlatform>x86</TargetPlatform>

    <!-- Any TargetFramework moniker or omit the whole tag for auto-detection. -->
    <!-- net48, [net40], net6.0, net5.0, netcoreapp3.1, uap10.0 etc. -->
    <TargetFrameworkVersion>net40</TargetFrameworkVersion>

    <!-- Path to Test Adapters -->
    <TestAdaptersPaths>%SystemDrive%\Temp\foo;%SystemDrive%\Temp\bar</TestAdaptersPaths>

    <!-- TestSessionTimeout was introduced in Visual Studio 2017 version 15.5 -->
    <!-- Specify timeout in milliseconds. A valid value should be greater than 0 -->
    <TestSessionTimeout>10000</TestSessionTimeout>

    <!-- true or false -->
    <!-- Value that specifies the exit code when no tests are discovered -->
    <TreatNoTestsAsError>true</TreatNoTestsAsError>
  </RunConfiguration>

  <!-- Configurations for data collectors -->
  <DataCollectionRunSettings>
    <DataCollectors>
      <DataCollector friendlyName="Code Coverage" uri="datacollector://Microsoft/CodeCoverage/2.0" assemblyQualifiedName="Microsoft.VisualStudio.Coverage.DynamicCoverageDataCollector, Microsoft.VisualStudio.TraceCollector, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
        <Configuration>
          <CodeCoverage>
            <ModulePaths>
              <Exclude>
                <ModulePath>.*CPPUnitTestFramework.*</ModulePath>
              </Exclude>
            </ModulePaths>

            <!-- We recommend you do not change the following values: -->
            <UseVerifiableInstrumentation>True</UseVerifiableInstrumentation>
            <AllowLowIntegrityProcesses>True</AllowLowIntegrityProcesses>
            <CollectFromChildProcesses>True</CollectFromChildProcesses>
            <CollectAspDotNet>False</CollectAspDotNet>

          </CodeCoverage>
        </Configuration>
      </DataCollector>

      <DataCollector uri="datacollector://microsoft/VideoRecorder/1.0" assemblyQualifiedName="Microsoft.VisualStudio.TestTools.DataCollection.VideoRecorder.VideoRecorderDataCollector, Microsoft.VisualStudio.TestTools.DataCollection.VideoRecorder, Version=15.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" friendlyName="Screen and Voice Recorder">
        <!--Video data collector was introduced in Visual Studio 2017 version 15.5 -->
        <Configuration>
          <!-- Set "sendRecordedMediaForPassedTestCase" to "false" to add video attachments to failed tests only -->
          <MediaRecorder sendRecordedMediaForPassedTestCase="true"  xmlns="">           ​
            <ScreenCaptureVideo bitRate="512" frameRate="2" quality="20" />​
          </MediaRecorder>​
        </Configuration>
      </DataCollector>

      <!-- Configuration for blame data collector -->
      <DataCollector friendlyName="blame" enabled="True">
      </DataCollector>

    </DataCollectors>
  </DataCollectionRunSettings>

  <!-- Parameters used by tests at run time -->
  <TestRunParameters>
    <Parameter name="webAppUrl" value="http://localhost" />
    <Parameter name="webAppUserName" value="Admin" />
    <Parameter name="webAppPassword" value="Password" />
  </TestRunParameters>

  <!-- Configuration for loggers -->
  <LoggerRunSettings>
    <Loggers>
      <Logger friendlyName="console" enabled="True">
        <Configuration>
            <Verbosity>quiet</Verbosity>
        </Configuration>
      </Logger>
      <Logger friendlyName="trx" enabled="True">
        <Configuration>
          <LogFileName>foo.trx</LogFileName>
        </Configuration>
      </Logger>
      <Logger friendlyName="html" enabled="True">
        <Configuration>
          <LogFileName>foo.html</LogFileName>
        </Configuration>
      </Logger>
      <Logger friendlyName="blame" enabled="True" />
    </Loggers>
  </LoggerRunSettings>

  <!-- Adapter Specific sections -->

  <!-- MSTest adapter -->
  <MSTest>
    <MapInconclusiveToFailed>True</MapInconclusiveToFailed>
    <CaptureTraceOutput>false</CaptureTraceOutput>
    <DeleteDeploymentDirectoryAfterTestRunIsComplete>False</DeleteDeploymentDirectoryAfterTestRunIsComplete>
    <DeploymentEnabled>False</DeploymentEnabled>
    <AssemblyResolution>
      <Directory path="D:\myfolder\bin\" includeSubDirectories="false"/>
    </AssemblyResolution>
  </MSTest>

</RunSettings>

Specify environment variables in the .runsettings file

Environment variables can be set in the .runsettings file, which can directly interact with the test host. Specifying environment variables in the .runsettings file is necessary to support nontrivial projects that require setting environment variables like DOTNET_ROOT. These variables are set while spawning the test host process and they are available in the host.

Example

The following code is a sample .runsettings file that passes environment variables:

<?xml version="1.0" encoding="utf-8"?>
<!-- File name extension must be .runsettings -->
<RunSettings>
  <RunConfiguration>
    <EnvironmentVariables>
      <!-- List of environment variables we want to set-->
      <DOTNET_ROOT>C:\ProgramFiles\dotnet</DOTNET_ROOT>
      <SDK_PATH>C:\Codebase\Sdk</SDK_PATH>
    </EnvironmentVariables>
  </RunConfiguration>
</RunSettings>

The RunConfiguration node should contain an EnvironmentVariables node. An environment variable can be specified as an element name and its value.

Note

Because these environment variables should always be set when the test host is started, the tests should always run in a separate process. For this, the /InIsolation flag will be set when there are environment variables so that the test host is always invoked.

See also