Testing in a Monorepo

Along with linting and building, testing is a crucial part of a production-ready monorepo. Whether you're using end-to-end tests or a unit test suite, integrating them with Turborepo will lead to enormous speed-ups.

Working with test runners

Let's say we have a monorepo that looks like this:

├── apps
│   └── web
│       └── package.json
└── packages
    └── shared
        └── package.json

Both apps/web and packages/shared have their own test suite. Their package.json files look like this:

{
  "scripts": {
    "test": "jest"
  }
}

Inside the root turbo.json, we recommend setting up a test task in your pipeline:

{
  "pipeline": {
    "test": {}
  }
}

Now, you can run turbo test and have Turborepo test the entire repository.

Because of Turborepo's caching, this also means that only repositories that have changed files will be tested - resulting in a lot of time saved.

Running tests in watch mode

When you run your test suite normally, it completes and outputs to stdout. This means you can cache it with Turborepo.

But when you run your tests in watched mode, the process never exits. This makes a watch task more like a development task.

Because of this difference, we recommend specifying two separate Turborepo tasks: one for running your tests, and one for running them in watch mode.

Here's an example:

{
  "scripts": {
    "test": "jest",
    "test:watch": "jest --watch"
  }
}

{
  "pipeline": {
    "test": {},
    "test:watch": {
      "cache": false
    }
  }
}

{
  "scripts": {
    "test": "turbo run test",
    "test:watch": "turbo run test:watch"
  }
}