Google Test Adapter / Test Adapter for Google Test

This README details the ‘Google Test Adapter’ GTA and the ‘Test Adapter for Google Test’ TAfGT, and . These test adapters are Visual Studio extensions that provide test discovery and execution of C++ tests written with the Google Test framework.

Microsoft collaborated with the creators of GTA to fork their project and create ‘Test Adapter for Google Test’. These test adapters share many of the same features and any differences will be explicitly labeled with [TAfGT] or [GTA] in this document. GTA may contain more experimental features, whereas all updates to TAfGT must go through Microsoft’s software development cycle.

Features

• Project and item templates for setting up unit tests based on the Google Test framework; the project template provides automatic acquisition and setup of the Google Test framework, making it easy to get started with writing unit tests
• Sequential and parallel test execution
• Traits support by means of custom C++ macros and/or trait assignment by regexes
• Support for value-parameterized, typed, and type-parameterized tests
• Google Test's runtime behavior (handling of exceptions, break on assertion failure) can be controlled via VS options
• Most important runtime options can be controlled via toolbar without entering VS's options
• Support for all Google Test command line options, including test shuffling and test repetition
• TFS support by means of VSTest.Console.exe
• Support for test case filters
• Failed assertions and SCOPED_TRACEs are linked to their source locations
• Identification of crashed tests
• Test output can be piped to test console
• Execution of parameterized batch files for test setup/teardown
• Test discovery using a custom regex (if needed) or an indicator file
• Settings can be shared via source control
• Installable as Visual Studio extension or [GTA] NuGet development dependency

History

• See TAFGT releases
• See GTA releases.

Usage

Installation

The adapters can be installed in several ways:

• Install through the Visual Studio Marketplace at Tools/Extensions and Updates - search for Test Adapter for Google Test or Google Test Adapter.
• Download and launch the VSIX installer from either the Visual Studio Marketplace (TAfGT, GTA) or GitHub
• [GTA only] Add a NuGet dependency to the Google test adapter nuget package to your Google Test projects. Note, however, that Visual Studio integration is limited this way: VS can discover and run tests, but no debugging, options or toolbar will be available; configuration is only possible through solution config files (see below).

After restarting VS, your tests will be displayed in the Test Explorer at build completion time. If no or not all tests show up, have a look at the troubleshooting section.

Configuration

There are several different ways to configure the adapter:

• The respective global options menus:
  • [TAfGT] Tools/Options/Test Adapter for Google Test
  • [GTA] Tools/Options/Google Test Adapter
• The toolbar (not available if installed via NuGet). Using the toolbar, you can set the most important runtime options (i.e., Parallel test execution, Break on failure, Catch exceptions, and Print test output); this is equivalent to setting the according options via Tools/Options menus detailed above. Open the toolbar via:
  • [TAfGT] Tools/Customize…/Test Adapter for Google Test
  • [GTA] Tools/Customize…/Google Test Adapter
• Solution settings files (not available if run via VsTest.Console.exe). They are provided by means of an XML configuration file; this allows sharing of settings via source control. The configuration file must be placed in the same folder as the solution's .sln file, and must have the same name as that file, but with extension .gta.runsettings. E.g., if the solution file's name is Foo.sln, the settings file must be named Foo.gta.runsettings.
• Visual Studio user settings files. VS allows for the selection of test settings files via the Test/Test Settings menu, and to pass such settings files to VsTest.Console.exe via the /Settings parameter.

The format of solution and user settings files is the same: a <GoogleTestAdapterSettings> node contains the solution settings and the (possibly empty) set of project settings and is itself contained in a <RunSettings> node (which in the case of user settings files might contain additional, e.g. VS specific settings). In contrast to solution settings, each set of project settings additionally has a regular expression to be evaluated at test discovery and execution time.

The final settings to be used are computed by merging the available settings, vaguely following Visual Studio's approach of configuration inheritance. Merging is done in two stages:

1. The available global, solution file, and user file settings are merged into solution settings and a set of project settings. This is done in increasing priority, i.e., solution file settings override global settings, and user file settings override solution settings. Project settings of solution and user settings files are merged if they share the exact same regular expression.
2. At test discovery and execution time, each test executable's full path is matched against the project settings' regular expressions; the first matching project settings are used for the particular test executable. If no project settings are found, the solution settings are used.

Overall, given a test executable mytests.exe, the following settings apply to that executable in decreasing priority:

1. Project settings of a user settings file, the regular expression of which matches the full path of mytests.exe.
2. Project settings of a solution settings file, the regular expression of which matches the full path of mytests.exe.
3. Solution settings of a user settings file.
4. Solution settings of a solution settings file.
5. Global settings.

Note that due to the overriding hierarchy described above, you probably want to provide only a subset of the nodes in your configuration files. For instance, providing the node <DebugMode>true</DebugMode> in a shared solution settings file will make sure that all sharing developers will run the test adapter with debug output, no matter what the developer's individual settings at Tools/Options/Test Adapter for Google Test are (and unless the developer has selected a test settings file via VS, which would override the solution setting).

For reference, see a settings file AllTestSettings.gta.runsettings containing all available settings, a more realistic solution settings file SampleTests.gta.runsettings as delivered with the SampleTests solution, and a user settings file NonDeterministic.runsettings as used by GTA's end-to-end tests.

Assigning traits to tests

The test adapters have full support for traits, which can be assigned to tests in two ways:

• You can make use of the custom test macros provided in GTA_Traits_1.8.0.h (or GTA_Traits_1.7.0.h if you are still on Google Test 1.7.0), which contain macros for all test types of the Google Test framework. The macros do not change behavior of the tests; they only add some information to the generated test code which encodes the traits assigned to the respective test. All GTA provided macros follow the same naming schema <Google Test macro>_TRAITS, where, obviously, <Google Test macro> is the name of the according macro in Google Test. Each test can be assigned up to 8 traits.
• Combinations of regular expressions and traits can be specified under the test adapter's options: If a test's name matches one of these regular expressions, the according trait is assigned to that test.

More precisely, traits are assigned to tests in three phases:

1. Traits are assigned to tests which match one of the regular expressions specified in the traits before option. For instance, the expression .*///Size,Medium assigns the trait (Size,Medium) to all tests.
2. Traits added to tests via test macros are assigned to the according tests, overriding traits from the first phase. For instance, the test declaration TEST_P_TRAITS(ParameterizedTests, SimpleTraits, Size, Small) will make sure that all test instances of test ParameterizedTest.SimpleTraits will be assigned the trait (Size,Small) (and override the Size trait assigned from the first phase).
3. Traits are assigned to tests which match one of the regular expressions specified in the traits after option, overriding traits from phases 1 and 2 as described above. For instance, the expression .*\[1.*\]///Size,Large will make sure that all parameterized tests where the parameter starts with a 1 will be assigned the trait (Size,Large) (and override the traits assigned by phases 1 and 2).

Note that traits are assigned in an additive manner within each phase, and in an overriding manner between phases. For instance, if a test is assigned the traits (Author,Foo) and (Author,Bar) in phase 1, the test will have both traits. If the test is also assigned the trait (Author,Baz) in phases 2 or 3, it will only have that trait. See test code for examples.

Running tests from command line with VSTest.Console.exe

The test adapters can be used to run tests from the command line, which can be done making use of VS's VSTest.Console.exe. They support all the tool's command line options, including /UseVsixExtensions and /TestAdapterPath.

Note, however, that VSTest.Console.exe will not make use of TAfGT/GTA solution settings (if the solution containing the tests happens to use such settings). All settings to be used by VSTest.Console.exe need to be passed using the /Settings command line option. Note also that the $(SolutionDir) placeholder is neither available in the Test setup/teardown batch file options nor in the Additional test execution parameters option.

The tests to be run can be selected via the /TestCaseFilter option. Filters need to follow the syntax as described in this blog entry. The adapters support the following test properties:

• DisplayName
• FullyQualifiedName
• Type
• Author
• TestCategory
• Source (i.e., binary containing the test)
• CodeFilePath (i.e., source file containing the test)
• Class
• LineNumber
• Id
• ExecutorUri

Additionally, traits can be used in test case filters. E.g., all tests having a Duration of short can be executed by means of the filter /TestCaseFilter:"Duration=short".

Parallelization

Tests are run sequentially by default. If parallel test execution is enabled, the tests will be distributed to the available cores of your machine. To support parallel test execution, additional command line parameters can be passed to the Google Test executables (note that this feature is not restricted to parallel test execution); they can then be parsed by the test code at run time and e.g. be used to improve test isolation.

This test adapter remembers the durations of the executed tests to improve test scheduling for later test runs. The durations are stored in files with endings .gta.testdurations - make sure your version control system ignores these files.

Note that since VS 2015 update 1, VS allows for the parallel execution of tests (again); since update 2, Test Explorer has an own Run tests in parallel button, and VsTest.Console.exe suppports a new command line option /Parallel. Neither button nor command line option has any effect on test execution with this test adapter.

Test setup and teardown

If you need to perform some setup or teardown tasks in addition to the setup/teardown methods of your test code, you can do so by configuring test setup/teardown batch files, to which you can pass several values such as solution directory or test directory for exclusive usage of the tests.

External resources

• Blog post for using Google Test with TAfGT in Visual Studio
• Basic tutorial for using Google Test with the Google Test Adapter in Visual Studio

Troubleshooting

None or not all of my tests show up

• Switch on

  • [TAfGT] Print debug info at Tools/Options/Test Adapter for Google Test/General
  • [GTA] Print debug info at Tools/Options/Google Test Adapter/General

• This will show on the test console whether your test executables are found by the adapter. If they are not, you have two options:

  • Configure a Regex for test discovery at the same place.
  • If your test executable is ..\FooTests.exe, make sure that a file ..\FooTests.exe.is_google_test exists.

• Your test executable can not run with command line option --gtest_list_tests, e.g. because it crashes. Make sure that your tests can be listed via command line; if they do not, debug your test executable, e.g. by making the according test project the startup project of your solution, and placing a breakpoint at the main method of your test executable.

• If your project configuration contains references to DLLs which do not end up in the build directory (e.g. through Project/Properties/Linker/Input/Additional Dependencies), these DLLs will not be found when running your tests. Use option PATH extension to add the directories containing these DLLs to the test executables' PATH variable.

• If your project happens to be a makefile project, there's a pitfall which will prevent the adapter from discovering your tests: It appears that when importing a makefile project into VS, the Output setting of the project is populated from the makefile's content. However, if the makefile is edited later on such that the location of the generated test executable changes, VS does not find the test executable any more. One symptom of this is that your project can not be launched any more with F5. Make sure that the Output setting of the project is consistent with its makefile to avoid this problem.

No source locations and traits are found for my tests

• The test adapter is not able to find the pdb of your test executable, e.g. because it has been deleted or moved (and indicates that with a warning in the test output window). Rebuilding your solution should regenerate the pdb at an appropriate location.
• The test executable's project settings result in a pdb file not containing the information necessary to resolve source locations and traits (see #46). Change the setting as indicated below and rebuild your solution.
  • VS 2015 and earlier: Yes or Optimize for debugging (/DEBUG)
  • VS 2017: Generate debug information optimized for sharing and publishing (/DEBUG:FULL)
• Option Parse symbol information is set to false, making the test adapter not parse that information out of the pdb file intentionally. The actual set of options used is potentially composed from VS options, a solution settings file, and a user settings file; the resulting set of options will be logged to the test output window if the Print debug info option is set to true.

The extension is disabled when I start Visual Studio

• Your MEF cache might have been corrupted. Please refer to this issue for help.

Development of Google Test Adapter [GTA]

Please refer to our wiki.

Credits

People

Test Adapter for Google Test is maintained by Microsoft.

The original Google Test Adapter is written and maintained by Christian Soltenborn (main author) and Jonas Gefele (regular contributor).

The first version of GTA was a slightly enhanced C# port of the F# Google Test Runner, written by Markus Lindqvist. We have also learned a lot from the JavaScript test runner Chutzpah, written by Matthew Manela.

Tools: Thanks from [GTA]

GTA has benefited from all kinds of contributions, be it feature requests, bug reports, code snippets, testing of new features and bugfixes, or even pull requests. Most (hopefully all) contributors are mentioned in the according release notes.

• ReSharper - awesome VS extension for .NET development, including refactoring, static analysis etc.
• thanks to JetBrains for providing free licenses for our developers!
• note that JetBrains' Resharper C++ can also run tests written using Google Test
• AppVeyor - awesome .NET CI build services
• thanks for providing free services and great support for open source projects!
• Codecov - code coverage visualization facilities
• thanks for providing free services for open source projects!
• CommonMark.NET - open source Markdown to HTML converter
• OpenCover - open source .NET code coverage