Most shared tests include a common test_helper.rb before running tests:

require_relative 'test_helper'
class MyNewTest < Minitest::Test
  include SetupTest

  def test_something
    # [...]
  end
end

This test helper includes:

• common test libraries (minitest, etc)
• webmock to disable external HTTP requests (use stubs when needed)

The included SetupTest module automatically wraps each test case with the following:

• VCR to record/replay external HTTP request fixtures
• truncating database tables to ensure repeatable tests
• enclosing each test in a rollback: always transaction, to leave behind no database side-effects

VCR is enabled automatically when include SetupTest is added to the test class extending Minitest::Test.

When you run a test that generates external HTTP requests, it will generate .yml fixture files within shared/test/fixtures/vcr/[test_class]/[test_name].yml. Make sure to git-add the .yml to commit it along with your new test.

When you modify a test in a way that changes the HTTP requests it generates, you will need to re-generate the fixtures. To do this, simply delete the relevant .yml files and run the rest again.

If tests depend on authorization or API keys (such as an AWS access/secret key) in order for them to succeed, simply make sure this information is available in the environment when running the test and generating the fixture. Also make sure that no sensitive information ends up in the generated fixtures before committing them. (See shared/test/common_test_helper.rb for examples of how to filter unnecessary or sensitive headers.)

See e.g. shared/test/test_sound_library_api.rb and the corresponding shared/test/fixtures/vcr/soundlibrary/get_deleted_sound.yml files for a simple reference.

For more information, refer to VCR's excellent documentation that explains its API usage in great detail.