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Microsoft.Testing.Platform and VSTest comparison

  • Article

Microsoft.Testing.Platform is a lightweight and portable alternative to VSTest for running tests in command line, in continuous integration (CI) pipelines, in Visual Studio Test Explorer, and in Visual Studio Code. In this article, you learn the key differences between the MSTest runner and VSTest.

Differences in test execution

Tests are executed in different ways depending on the runner.

Execute VSTest tests

VSTest ships with Visual Studio, the .NET SDK, and as a standalone tool in the Microsoft.TestPlatform NuGet package. VSTest uses a runner executable to run tests, called vstest.console.exe, which can be used directly or through dotnet test.

Execute Microsoft.Testing.Platform tests

Microsoft.Testing.Platform is embedded directly into your test project and doesn't ship any extra executables. When you run your project executable, your tests run. For more information on running Microsoft.Testing.Platform tests, see Microsoft.Testing.Platform overview: Run and debug tests.

Namespaces and NuGet packages

To familiarize yourself with Microsoft.Testing.Platform and VSTest, it's helpful to understand the namespaces and NuGet packages that are used by each.

VSTest namespaces

VSTest is a collection of testing tools that are also known as the Test Platform. The VSTest source code is open-source and available in the microsoft/vstest GitHub repository. The code uses the Microsoft.TestPlatform.* namespace.

VSTest is extensible and common types are placed in Microsoft.TestPlatform.ObjectModel NuGet package.

Microsoft.Testing.Platform namespaces

Microsoft.Testing.Platform is based on Microsoft.Testing.Platform NuGet package and other libraries in the Microsoft.Testing.* namespace. Like VSTest, the Microsoft.Testing.Platform is open-source and has a microsoft/testfx GitHub repository.

Communication protocol (preview)

Note

The Visual Studio Test Explorer supports the Microsoft.Testing.Platform protocol in the preview versions since 17.10 onward. If you run/debug your tests using earlier versions of Visual Studio, Test Explorer will use vstest.console.exe and the old protocol to run these tests.

Microsoft.Testing.Platform uses a JSON-RPC based protocol to communicate between Visual Studio and the test runner process. The protocol is documented in the MSTest GitHub repository.

VSTest also uses a JSON based communication protocol, but it's not JSON-RPC based.

Disabling the new protocol

To disable the use of the new protocol in Test Explorer, you can edit your project to add the following property: <DisableTestingPlatformServerCapability>true</DisableTestingPlatformServerCapability>.

Executables

VSTest ships multiple executables, notably vstest.console.exe, testhost.exe, and datacollector.exe. However, MSTest is embedded directly into your test project and doesn't ship any other executables. The executable your test project compiles to is used to host all the testing tools and carry out all the tasks needed to run tests.

Migrating from VSTest

In addition to the steps specific to your test framework, you need to update your test infrastructure to accommodate to Microsoft.Testing.Platform.

dotnet test

Command line options of dotnet test are divided into 2 categories: build related arguments and test related ones.

The build related arguments are passed to the dotnet build command and as such don't need to be updated for the new platform. Build related arguments are listed below:

  • -a|--arch <ARCHITECTURE>
  • --artifacts-path <ARTIFACTS_DIR>
  • -c|--configuration <CONFIGURATION>
  • -f|--framework <FRAMEWORK>
  • -e|--environment <NAME="VALUE">
  • --interactive
  • --no-build
  • --nologo
  • --no-restore
  • -o|--output <OUTPUT_DIRECTORY>
  • --os <OS>
  • -r|--runtime <RUNTIME_IDENTIFIER>
  • -v|--verbosity <LEVEL>

The test related arguments are VSTest specific and so need to be transformed to match the new platform. The following table shows the mapping between the VSTest arguments and the new platform:

VSTest argument New platform argument
--test-adapter-path <ADAPTER_PATH> Not supported
--blame Not supported
--blame-crash --crashdump requires Crash dump extension
--blame-crash-dump-type <DUMP_TYPE> --crashdump-type requires Crash dump extension
--blame-crash-collect-always Not supported
--blame-hang --hangdump requires Hang dump extension
--blame-hang-dump-type <DUMP_TYPE> --hangdump-type requires Hang dump extension
--blame-hang-timeout <TIMESPAN> --hangdump-timeout requires Hang dump extension
--collect <DATA_COLLECTOR_NAME> Depends on the data collector
-d\|--diag <LOG_FILE> --diagnostic
--filter <EXPRESSION> Depends upon the selected test framework
-l\|--logger <LOGGER> Depends on the logger
--results-directory <RESULTS_DIR> --results-directory <RESULTS_DIR>
-s\|--settings <SETTINGS_FILE> Depends upon the selected test framework
-t\|--list-tests --list-tests
-- <RunSettings arguments> Not supported

Important

Before specifying any Microsoft.Testing.Platform arguments, you need to add -- to separate the dotnet test arguments from the new platform arguments. For example, dotnet test --no-build -- --list-tests.

vstest.console.exe

If you are using vstest.console.exe directly, we recommend replacing it with the dotnet test command.

Test Explorer

When using Visual Studio or Visual Studio Code Test Explorer, you might need to enable the support for the new test platform.

Visual Studio

Visual Studio Test Explorer supports the new test platform starting with version 17.14. If you are using an earlier version, you might need to update your Visual Studio to the latest version.

Visual Studio Code

Visual Studio Code Test Explorer supports the new test platform starting with version X.

Azure DevOps

When using Azure DevOps tasks, you might need to update your pipeline to use the new test platform.

VSTest task

If you are using the VSTest task in Azure DevOps, you can replace it with the .NET Core task.

.NET Core task

If you are using the .NET Core task, no changes are needed.