### New features

* [#278](https://github.com/rubocop/rubocop-minitest/pull/278): Add new `RuboCop::TestCase` as a stable API for testing custom cops with Minitest. The cop under test is derived from the test class name and can be configured with `cop_class`, `cop_config`, `other_cops`, and `target_ruby_version`. ([@koic][])

### Changes

* [#345](https://github.com/rubocop/rubocop-minitest/pull/345): Fix false positives and negatives in `Minitest/NonExecutableTestMethod` for nested test classes and for test methods defined before the test class. ([@amckinnie][])
* [#278](https://github.com/rubocop/rubocop-minitest/pull/278): **(Breaking)** Remove the cop argument from `inspect_source` and `investigate` in the Minitest test support; the cop under test is now resolved automatically. The test configuration now merges the default configuration for the cop under test and sets `AllCops: TargetRubyVersion` explicitly. ([@koic][])

[@koic]: https://github.com/koic
[@amckinnie]: https://github.com/amckinnie
