Building a Design System Monorepo with Turborepo

Lee Robinson

Lee Robinson / March 29, 2019

6 min read––– views

This guide explains how to use a React design system starter powered by:

  • 🏎 Turborepo — High-performance build system for Monorepos
  • 🚀 React — JavaScript library for user interfaces
  • 🛠 Tsup — TypeScript bundler powered by esbuild
  • 📖 Storybook — UI component environment powered by Vite

As well as a few others tools preconfigured:

Getting Started

Clone the design system example locally or from GitHub:

npx degit vercel/turborepo/examples/design-system design-system
cd design-system
yarn install
git init . && git add . && git commit -m "Init"

Useful Commands

  • yarn build - Build all packages including the Storybook site
  • yarn dev - Run all packages locally and preview with Storybook
  • yarn lint - Lint all packages
  • yarn changeset - Generate a changeset
  • yarn clean - Clean up all node_modules and dist folders (runs each package's clean script)

Turborepo

Turborepo is a high-performance build system for JavaScript and TypeScript codebases. It was designed after the workflows used by massive software engineering organizations to ship code at scale. Turborepo abstracts the complex configuration needed for monorepos and provides fast, incremental builds with zero-configuration remote caching.

Using Turborepo simplifes managing your design system monorepo, as you can have a single lint, build, test, and release process for all packages. Learn more about how monorepos improve your development workflow.

Apps & Packages

This Turborepo includes the following packages and applications:

  • apps/docs: Component documentation site with Storybook
  • packages/@acme/core: Core React components
  • packages/@acme/utils: Shared React utilities
  • packages/@acme/tsconfig: Shared tsconfig.jsons used throughout the Turborepo
  • packages/eslint-preset-acme: ESLint preset

Each package and app is 100% TypeScript. Yarn Workspaces enables us to "hoist" dependencies that are shared between packages to the root package.json. This means smaller node_modules folders and a better local dev experience. To install a dependency for the entire monorepo, use the -W workspaces flag with yarn add.

This example sets up your .gitignore to exclude all generated files, other folders like node_modules used to store your dependencies.

Compilation

To make the core library code work across all browsers, we need to compile the raw TypeScript and React code to plain JavaScript. We can accomplish this with tsup, which uses esbuild to greatly improve performance.

Running yarn build from the root of the Turborepo will run the build command defined in each package's package.json file. Turborepo runs each build in parallel and caches & hashes the output to speed up future builds.

For acme-core, the build command is the following:

tsup src/index.tsx --format esm,cjs --dts --external react

tsup compiles src/index.tsx, which exports all of the components in the design system, into both ES Modules and CommonJS formats as well as their TypeScript types. The package.json for acme-core then instructs the consumer to select the correct format:

acme-core/package.json
{
  "name": "@acme/core",
  "version": "0.0.0",
  "main": "./dist/index.js",
  "module": "./dist/index.mjs",
  "types": "./dist/index.d.ts",
  "sideEffects": false,
}

Run yarn build to confirm compilation is working correctly. You should see a folder acme-core/dist which contains the compiled output.

acme-core
└── dist
    ├── index.t.ts  <-- Types
    ├── index.js    <-- CommonJS version
    └── index.mjs   <-- ES Modules version

Components

Each file inside of acme-core/src is a component inside our design system. For example:

acme-core/src/Button.tsx
import * as React from 'react';

export interface ButtonProps {
  children: React.ReactNode;
}

export function Button(props: ButtonProps) {
  return <button>{props.children}</button>;
}

Button.displayName = 'Button';

When adding a new file, ensure the component is also exported from the entry index.tsx file:

acme-core/src/index.tsx
import * as React from "react";
export { Button, type ButtonProps } from "./Button";
// Add new component exports here

Storybook

Storybook provides us with an interactive UI playground for our components. This allows us to preview our components in the browser and instantly see changes when developing locally. This example preconfigures Storybook to:

  • Use Vite to bundle stories instantly (in milliseconds)
  • Automatically find any stories inside the stories/ folder
  • Support using module path aliases like @acme/core for imports
  • Write MDX for component documentation pages

For example, here's the included Story for our Button component:

apps/docs/stories/button.stories.mdx
import { Button } from '@acme/core/src';
import { Meta, Story, Preview, Props } from '@storybook/addon-docs/blocks';

<Meta title="Components/Button" component={Button} />

# Button

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec euismod, nisl eget consectetur tempor, nisl nunc egestas nisi, euismod aliquam nisl nunc euismod.

## Props

<Props of={Box} />

## Examples

<Preview>
  <Story name="Default">
    <Button>Hello</Button>
  </Story>
</Preview>

This example includes a few helpful Storybook scripts:

  • yarn dev: Starts Storybook in dev mode with hot reloading at localhost:6006
  • yarn build: Builds the Storybook UI and generates the static HTML files
  • yarn preview-storybook: Starts a local server to view the generated Storybook UI

Versioning & Publishing Packages

This example uses Changesets to manage versions, create changelogs, and publish to npm. It's preconfigured so you can start publishing packages immediatley.

You'll need to create an NPM_TOKEN and GITHUB_TOKEN and add it to your GitHub repository settings to enable access to npm. It's also worth installing the Changesets bot on your repository.

Generating the Changelog

To generate your changelog, run yarn changeset locally:

  1. Which packages would you like to include? – This shows which packages and changed and which have remained the same. By default, no packages are included. Press space to select the packages you want to include in the changeset.
  2. Which packages should have a major bump? – Press space to select the packages you want to bump versions for.
  3. If doing the first major version, confirm you want to release.
  4. Write a summary for the changes.
  5. Confirm the changeset looks as expected.
  6. A new Markdown file will be created in the changeset folder with the summary and a list of the packages included.

Releasing

When you push your code to GitHub, the GitHub Action will run the release script defined in the root package.json:

turbo run build --filter=docs^... && changeset publish

Turborepo runs the build script for all publishable packages (excluding docs) and publishes the packages to npm. By default, this example includes acme as the npm organization. To change this, do the following:

  • Rename folders in packages/* to replace acme with your desired scope
  • Search and replace acme with your desired scope
  • Re-run yarn install

To publish packages to a private npm organization scope, remove the following from each of the package.json's

- "publishConfig": {
-  "access": "public"
- },

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