What to Cache?

By default, the console output from all tasks is always captured by Turborepo. If your task does not emit any files (e.g. unit tests with Jest) you can omit outputs. Beyond that, you will generally need to specify which files on disk you need to capture (and restore!) in order to be able to run subsequent dependent tasks.

Configuring Cache Outputs

You configure cache outputs in Turborepo by passing specifying an array of globs inside pipeline.<task>.outputs as seen in this example:

{
  "$schema": "https://turbo.build/schema.json",
  "pipeline": {
    "build": {
      "outputs": ["dist/**"]
    }
  }
}

Inclusions

In the above task definition for build it should be noted that it applies to all of the build tasks in the entire Turborepo. It's quite likely that each of those individual tasks have slight differences in where their outputs are located, especially as the repository grows.

For example, you may have a utility workspace whose artifacts produced during build appear in lib instead of dist, meaning that the definition that you had previously would not work for both of the utility and your application whose output artifacts appear in dist.

There are two ways to address this. The first option is to include the lib directory into the outputs:

{
  "$schema": "https://turbo.build/schema.json",
  "pipeline": {
    "build": {
      "outputs": ["dist/**", "lib/**"]
    }
  }
}

This pattern will work well as long as the dist and lib folders start empty for all of the workspaces in the turborepo. turbo will capture all of the files that appear in those folders.

However, if the pattern isn't consistent enough across all of the workspaces, you can define those per-workspace, or use workspace configurations.

{
  "$schema": "https://turbo.build/schema.json",
  "pipeline": {
    "app#build": {
      "outputs": ["dist/**"]
    },
    "util#build": {
      "outputs": ["lib/**"]
    }
  }
}

You'll notice that you must specify all of the files inside of a directory using the /** operator. Simply specifying a directory name (e.g. lib) will include just the directory itself, not its contents.

Exclusions

Sometimes the easiest way to specify which files need to be cached is to specify a combination of files to include, and which files in the included set should be excluded.

For example, the simplest configuration for a Next.js application with the default settings looks like this:

{
  "$schema": "https://turbo.build/schema.json",
  "pipeline": {
    "app#build": {
      "outputs": [".next/**", "!.next/cache/**"],
    }
  }
}

To exclude files you may specify a glob pattern with a leading ! to exclude anything that matches.