Monorepo with Lerna & Yarn Workspaces

• 🐉 Lerna  - The Monorepo manager
• 📦 Yarn Workspaces  -  Sane multi-package management
• 🛠 Babel  -  Compiles next-gen JavaScript
• 🃏 Jest  -  Unit/Snapshot Testing

Usage

• yarn bootstrap - This installs all of the packages and links dependent packages together.
• yarn build - This babelfies all of the packages and creates /lib folders for each one.
• yarn test - Run all linting and unit tests before committing.
• yarn test -o - Run only the tests that have changed.
• yarn test -u - Update all of the snapshot tests.

Lerna

• lerna changed - Show which packages have changed.
• lerna diff - Show specifically what files have cause the packages to change.

FAQ

Why the limitation on yarn versions?

It's a known issue that yarn workspaces using yarn versions > 1.18.0 can produce the following false positive error message when adding or updating dependencies in packages.

error An unexpected error occurred: "expected workspace package to exist for "XXX".

To guard against this, we've:

• Changed package.json to enforce a yarn version range.
• Added a .yvmrc file, so if you're using yvm to manage your yarn versions (like nvm for node version), it'll pick up the yarn version automatically.