minitest

To use Captain with minitest, you need to configure your test suite to output test results to a file and then tell Captain where to find those test results.

Getting Started

minitest does not natively produce a test results artifact that Captain can parse. To integrate, you'll need to install and configure the minitest-reporters gem. Once installed, you can configure it by making these changes to your test_helper.rb file:

# test_helper.rb
require "minitest/reporters"

Minitest::Reporters.use!(
  [
    Minitest::Reporters::DefaultReporter.new,
    Minitest::Reporters::JUnitReporter.new("tmp/reports", true, single_file: true)
  ]
)

Once you have minitest-reporters set up, configure Captain by creating a .captain/config.yml file in the root directory of your repository:

test-suites:
  your-project-minitest:
    command: bin/rails test
    results:
      language: Ruby
      framework: minitest
      path: tmp/reports/*.xml

You can change your-project-minitest to any name you like, but we typically recommend using the name of your project followed by a dash followed by minitest. The command is the command you already use to run your test suite. Captain will invoke this command to run your tests. The example above shows what you might use if you use bin/rails test and want to store test results in tmp/reports.

Once Captain is configured, you can run captain run your-project-minitest --print-summary. If you see your typical test output followed by a captain block like this:

--------------------------------------------------------------------------------
----------------------------------- Captain ------------------------------------
--------------------------------------------------------------------------------

then you've configured everything correctly! You can now supercharge your test framework's capabilities. See below for configuring each of Captain's features.

Identifying Tests

Captain uses framework specific "identity recipes" to identify the tests in your suite. These recipes are order dependent components extracted from native test framework output.

We use this identity to track the executions of a test over the course of their lifetime in your suite. This enables us to do things like flake detection, quarantining, and retries.

For minitest, Captain constructs the identity by parsing out the file and description attributes.

Quarantining Tests

Captain makes managing flaky tests easier than ever. When a test is identified as flaky, you can quarantine the test without modifying it, so that if only those tests fail, Captain reports a success with a 0 exit code. Unlike skipped tests, quarantined tests will continue to run, so you can still view their failure messages and see how frequently they are failing.

You can quarantine tests in OSS mode with captain add quarantine like so:

captain add quarantine your-project-minitest \
  --file test/example_test.rb \
  --description "TestExample#test_returns_one"

See the OSS quarantining guide for more information on managing quarantined tests in OSS mode.

Retrying Tests

You can configure Captain to automatically retry failed tests to help you determine if failing tests are flaky or are genuinely failing. To configure retries, update your .captain/config.yml file like so:

test-suites:
  your-project-minitest:
    command: bin/rails test
    results:
      language: Ruby
      framework: minitest
      path: tmp/reports/*.xml
    output:
      print-summary: true
    retries:
      attempts: 2
      command: bin/rails test {{ tests }}

Once configured, Captain will invoke your original test command, check for any failures, and retry your tests however many times you've specified (in this example, two additional times) by templating the failures into the command specified by retries.command. The output.print-summary option is not required, but we've added it for convenience in understanding the overall results after the retries have been factored in.

Partitioning

Captain can optimally partition your test suite's files into multiple groups for execution on multiple CI nodes. Captain tracks your test file runtime so that it can balance each partition.

Configure partitioning in .captain/config.yml:

test-suites:
  your-project-minitest:
    command: bin/rails test
    results:
      language: Ruby
      framework: minitest
      path: tmp/reports/*.xml
    output:
      print-summary: true
    partition:
      command: bin/rails test {{ testFiles }}
      globs:
        - test/**/*_test.rb

Captain will fill in the testFiles placeholder of your partition.command with the files resulting from expanding your configured partition.globs.

Then partition across your CI provider's parallel jobs:

# .rwx/ci.yml

tasks:
  - key: code
    call: git/clone 2.0.7

  - key: ruby
    call: ruby/install 1.2.30
    with:
      ruby-version: 3.3.0

  - key: deps
    use: [code, ruby]
    run: bundle install

  - key: captain
    call: rwx/install-captain 1.1.6

  - key: minitest
    use: [deps, captain]
    parallel: 8
    run: captain run your-project-minitest