minitest-distributed

https://github.com/Shopify/minitest-distributed

minitest-distributed is a plugin for minitest for executing tests on a distributed set of unreliable workers. When a test suite grows large enough, it inevitable gets too slow to run on a single machine to give timely feedback to developers. This plugins combats this issue by distributing the full test suite to a set of workers. Every worker is a consuming from a single queue, so the tests get evenly distributed and all workers will finish around the same time. Redis is used as coordinator, but when using this plugin without having access to Redis, it will use an in-memory coordinator. Using multiple (virtual) machines for a test run is an (additional) source of flakiness. To combat flakiness, minitest-distributed implements resiliency patterns, like re-running a test on a different worker on failure, and a circuit breaker for misbehaving workers.