FasterTests - parallel unit test runner

FasterTests is a console unit tests runner that can execute your regular tests in parallel to run them faster. Moreover, you will not need to change your existing test code for that.

You can download FasterTests from GitHub or install it from NuGet:

Install-Package FasterTests

Then run it from console as any other test runner:

FasterTests-Run "My.NUnit.Tests.Assembly.dll" -ExcludeCategories "Slow,Full"

This will run all tests from your test assembly except those marked with "Slow" and "Full" categories. Tests will be running in several parallel threads, each thread with its own AppDomain.

You can adjust runner behavior with optional command-line arguments:

• -IncludeCategories - comma-separated list of test categories to include into run
• -ExcludeCategories - comma-separated list of test categories to exclude from run
• -DegreeOfParallelism - parallel threads count. Defaults to machine logical processors (usually cores) count
• -Help - shows help about command-line arguments

Handling conflicting tests

Some tests are failing when executed in parallel due to conflicts - common example is DB tests. FasterTests provides two workarounds to solve this problem:

Group tests which can't run in parallel

You can group together tests which cannot run in parallel using -NoParallelGroups argument. Example:

FasterTests-Run "My.NUnit.Tests.Assembly.dll" -NoParallelGroups "Tests.Database.;Tests.Elastic.,Tests.Solr."

In this example, test classes which full name starts with "Tests.Database." will not run in parallel with other such tests. It is true for the second group as well - tests that have names starting with "Tests.Elastic." or "Tests.Solr." will not run in parallel with other tests in the same namespaces.

Patch test config per thread

You can tell FasterTests to patch certain strings in test assembly .config file before running test in each of the threads using -ConfigStringsToPatch argument. Example:

FasterTests-Run "My.NUnit.Tests.Assembly.dll" -ConfigStringsToPatch "=test_db,=other_test_db"

Here FasterTests will patch tests .config for each thread by searching for provided substrings (comma-separated) and adding thread index numeric suffix to them (for all threads except the first one). So if 3 threads are running tests in parallel then substring "=test_db" will be replaced with "=test_db_2" for thread #2 and "=test_db_3" for thread #3, and the same will be true for "=other_test_db".

This is useful for storage tests (like DB tests) to make sure that each test thread uses its own storage.

Known limitations

Work on FasterTests is in progress so it has some limitations (a.k.a. project TODO list):

• Works for NUnit tests only
• Cannot output results in NUnit XML or TeamCity formats
• Always creates threads in the same process, with dedicated AppDomains
• Cannot process more than one test assembly
• Cannot run specific test - you can only provide categories to include/exclude
• No ReSharper and/or VS plugin

Other runners

There are other free parallel NUnit test runners out there. Some of them are more mature and feature-rich, but FasterTests seems to be faster :) If FasterTests will not fit your requirements then maybe other runners will.

Here are links to some other parallel runners I have discovered:

• https://github.com/nunit/dev/wiki/Framework-Parallel-Test-Execution
• https://cpntr.codeplex.com/
• https://nunitmulticore.codeplex.com/
• http://www.codeproject.com/Tips/134389/Running-NUnit-tests-in-parallel
• https://github.com/Ancestry/ParallelizeNunit
• https://github.com/faisalmansoor/ParallelNUnit
• https://github.com/opentable/nunit-parallel-runner
• https://github.com/fourth/TestRunner