How to create a React library

Walkthrough for setting up a React Library repo with Github, React, Typescript, Rollup and Emotion.

Sources:

• Creating a React Component Library using Rollup, Typescript, Sass and Storybook
• 3 Ways to Build Your Own React Component Library
• create-react-library - Github

Development:

yarn install
yarn watch

• To run the build process of the component library in watch mode

cd example
yarn install
yarn start

• To run the example React app in development mode
• This way the component library will re-build and the example React app will re-compile every time a file changes.

Walkthrough:

1. Create a new repository on Github

• Initialize repo with a README
• Add .gitignore with Node.js presets
• Add an MIT License

2. Initialize package

• Run yarn init

3. Install react and react-dom as peerDependencies

• yarn add -D react react-dom @types/react
• Set them as peerDependencies in package.json (use the version you want to support):

...
"peerDependencies": {
  "react": ">=16.8.0",
  "react-dom": ">=16.8.0"
}
...

4. Install and configure typescript

• yarn add -D typescript
• Add the following tsconfig.json file in root:

{
  "compilerOptions": {
    "outDir": "dist",
    "module": "esnext",
    "lib": ["es6", "dom", "esnext"],
    "target": "es5",
    "moduleResolution": "node",
    "jsx": "react",
    "sourceMap": true,
    "declaration": true,
    "declarationDir": "dist",
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "forceConsistentCasingInFileNames": true,
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noEmit": true
  },
  "include": ["src/**/*"],
  "exclude": [
    "node_modules",
    "dist",
    "example/build",
    "src/**/*.stories.tsx",
    "src/**/*.test.tsx"
  ]
}

5. Create example component and install emotion

• yarn add -D @emotion/core @emotion/styled
• Add the following folder structure:

src/
  TestComponent/
    index.ts
    TestComponent.tsx
  index.ts

• TestComponent.tsx:

/** @jsx jsx */
import { css, jsx } from '@emotion/core';

export interface TestComponentProps {
  color: 'darkgreen' | 'lightgreen';
}

const TestComponent: React.FC<TestComponentProps> = ({ color }) => (
  <div
    css={css`
      background-color: hotpink;
      &:hover {
        color: ${color};
      }
    `}
  >
    This is a {color} component with a hotpink background.
  </div>
);

export default TestComponent;

• In src/index.ts, make sure to use named exports (Source):

export { default as TestComponent } from './TestComponent';

6. Install rollup and plugins

• yarn add -D rollup rollup-plugin-typescript2 @rollup/plugin-commonjs @rollup/plugin-node-resolve rollup-plugin-peer-deps-external
• Add the following rollup.config.js file in root:

import peerDepsExternal from 'rollup-plugin-peer-deps-external';
import resolve from '@rollup/plugin-node-resolve';
import commonjs from '@rollup/plugin-commonjs';
import typescript from 'rollup-plugin-typescript2';

const packageJson = require('./package.json');

export default {
  input: 'src/index.ts',
  output: [
    {
      file: packageJson.main,
      format: 'cjs',
      sourcemap: true
    },
    {
      file: packageJson.module,
      format: 'esm',
      sourcemap: true
    }
  ],
  plugins: [
    peerDepsExternal(),
    resolve(),
    commonjs(),
    typescript({ useTsconfigDeclarationDir: true })
  ]
};

• Add the following config variables and scripts in package.json:

...
"main": "dist/index.js",
"module": "dist/index.es.js",
"files": ["dist"],
"types": "dist/index.d.ts",
"scripts": {
  "build": "rollup -c",
  "watch": "rollup -cw"
},
...

• Run yarn build

8. Generate example React app with create-react-app

• npx create-react-app example --template typescript

9. Install the example app's dependencies in the parent package

• yarn add -D @testing-library/jest-dom @testing-library/react @testing-library/user-event @types/jest @types/node @types/react-dom react-scripts

10. Link the example app's dependencies to the ones installed to the parent

...
  "dependencies": {
    ...
    "react": "link:../node_modules/react",
    "react-dom": "link:../node_modules/react-dom",
    "react-scripts": "link:../node_modules/react-scripts",
    ...
  },
  ...
  "scripts": {
    "start": "node ../node_modules/react-scripts/bin/react-scripts.js start",
    ...
  },
  ...

• Add a link to the development package in package.json:

  ...
  "dependencies": {
    ...
    "how-to-create-a-react-lib": "link:.."
  },
  ...

11. Use the development package in the example app

• Run yarn install in the example app
• Import the development package in the App.tsx:

import { TestComponent } from 'how-to-create-a-react-lib';

12. Develop the library and run the example app

yarn watch
cd example && yarn start

• Change the code in the src/ folder

Deploying the example app to Github Pages (Source)

• Add a homepage variable to both ./package.json and ./example/package.json (Optional)
  • Per CRA docs: we need to set the homepage variable if we use routing in our app
  • Use the base path where you will be serving the React app from. (More info)

...
"homepage": "http://andrewszucs.github.io/how-to-create-a-react-lib",
...

• yarn add -D gh-pages

• Add the following scripts to package.json in root:

  • I needed the clean script because I ran into this issue saying: fatal: A branch named 'gh-pages' already exists.

...
"scripts": {
  ...
  "clean" : "gh-pages-clean",
  "predeploy": "cd example && yarn install && yarn build",
  "deploy": "gh-pages -d example/build"
  ...
}
...

• Run yarn deploy
  • This will create a new branch named gh-pages commit the example/build folder to that branch, push it to our Github repo and set it as the base for Github Pages.

Setting up ESLint, Prettier, Husky and Lint-staged for code quality

1. Add ESLint with the eslint-config-react-app preset

• yarn add -D eslint-config-react-app @typescript-eslint/[email protected] @typescript-eslint/[email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected]
• Create an .eslintrc.json file and add the following:

{
  "extends": ["react-app"],
  /** These are optional: */
  "rules": {
    /** Warn if console.log are added */
    "no-console": "warn",

    /** Enforcing rules about import ordering */
    "import/order": [
      "warn",
      {
        "groups": [["builtin", "external"], "internal", ["parent", "sibling", "index"]],
        "newlines-between": "always-and-inside-groups"
      }
    ]
  }
}

2. Add Prettier and integrate it with ESLint

• yarn add -D prettier eslint-config-prettier eslint-plugin-prettier
• Add plugin:prettier/recommended to the extends array in eslintrc.json:

{
  "extends": [..., "plugin:prettier/recommended"],
  ...
}

• Add a .prettierrc file to configure Prettier:

{
  "semi": true,
  "singleQuote": true,
  "jsxSingleQuote": true,
  "trailingComma": "none",
  "tabWidth": 2,
  "bracketSpacing": true,
  "jsxBracketSameLine": false,
  "arrowParens": "always",
  "printWidth": 90
}

3. Add husky and lint-staged to lint and format at each commit

• yarn add -D husky lint-staged

• Add a lint and a format script to package.json:

"scripts": {
  "lint": "eslint . --max-warnings=0",
  "format": "prettier --write \"**/*.+(js|jsx|ts|tsx|json|yml|yaml|css|md|vue)\"",
}

• Add the husky and lint-staged config to package.json:

"husky": {
    "hooks": {
      "pre-commit": "yarn lint && yarn format"
    }
  },
"lint-staged": {
  "*.+(js|jsx|ts|tsx)": [
    "eslint --fix",
    "git add"
  ],
  "*.+(json|css|md)": [
    "prettier --write",
    "git add"
  ]
},

4. Add a script for running Typescript check

• Add the following to scripts in package.json:

...
"scripts": {
  ...
  "typecheck": "tsc -p ./tsconfig.json",
  "typecheck:watch": "yarn typecheck --watch"
}
...

Adding Minification to the build process

• yarn add -D rollup-plugin-uglify rollup-plugin-terser
• Change rollup.config.js

Setting up semantic-release and Github Actions workflow

• npx semantic-release-cli setup
• Add this to package.json:

{
  "publishConfig": {
    "registry": "https://npm.pkg.github.com/",
    "pkgRoot": "build"
  }
}

• Change back version in package.json:

"version":"1.0.0"

• Add .releaserc.json to configure semantic-release:

{
  "branches": "master",
  "repositoryUrl": "https://github.com/andrewszucs/how-to-create-a-react-lib",
  "debug": "true",
  "plugins": [
    "@semantic-release/commit-analyzer",
    "@semantic-release/release-notes-generator",
    "@semantic-release/npm",
    "@semantic-release/github",
    [
      "@semantic-release/changelog",
      {
        "changelogFile": "CHANGELOG.md"
      }
    ],
    [
      "@semantic-release/git",
      {
        "assets": ["package.json", "package-lock.json", "CHANGELOG.md"],
        "message": "chore(release): ${nextRelease.version} [skip ci]\n\n${nextRelease.notes}"
      }
    ]
  ]
}

• yarn add -D @semantic-release/git @semantic-release/changelog

Need to add a bot user with zero vulnerabilities to push

• GITHUB_TOKEN is not defined

[11:08:54 PM] [semantic-release] › ✖  Failed step "prepare" of plugin "@semantic-release/git"
[11:08:54 PM] [semantic-release] › ✖  An error occurred while running semantic-release: Error: Command failed with exit code 1: git push --tags https://github.com/andrewszucs/how-to-create-a-react-lib HEAD:master
remote: error: GH006: Protected branch update failed for refs/heads/master.
remote: error: Required status check "Test code" is expected. At least 1 approving review is required by reviewers with write access.
To https://github.com/andrewszucs/how-to-create-a-react-lib
 ! [remote rejected] HEAD -> master (protected branch hook declined)
error: failed to push some refs to 'https://github.com/andrewszucs/how-to-create-a-react-lib'
    at makeError (/home/runner/work/how-to-create-a-react-lib/how-to-create-a-react-lib/node_modules/@semantic-release/git/node_modules/execa/lib/error.js:59:11)
    at handlePromise (/home/runner/work/how-to-create-a-react-lib/how-to-create-a-react-lib/node_modules/@semantic-release/git/node_modules/execa/index.js:114:26)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async push (/home/runner/work/how-to-create-a-react-lib/how-to-create-a-react-lib/node_modules/@semantic-release/git/lib/git.js:51:3)
    at async module.exports (/home/runner/work/how-to-create-a-react-lib/how-to-create-a-react-lib/node_modules/@semantic-release/git/lib/prepare.js:69:5)
    at async prepare (/home/runner/work/how-to-create-a-react-lib/how-to-create-a-react-lib/node_modules/@semantic-release/git/index.js:28:3)
    at async validator (/home/runner/work/how-to-create-a-react-lib/how-to-create-a-react-lib/node_modules/semantic-release/lib/plugins/normalize.js:34:24)
    at async /home/runner/work/how-to-create-a-react-lib/how-to-create-a-react-lib/node_modules/semantic-release/lib/plugins/pipeline.js:37:34
    at async /home/runner/work/how-to-create-a-react-lib/how-to-create-a-react-lib/node_modules/semantic-release/lib/plugins/pipeline.js:31:3
    at async Object.pluginsConf.<computed> [as prepare] (/home/runner/work/how-to-create-a-react-lib/how-to-create-a-react-lib/node_modules/semantic-release/lib/plugins/index.js:80:11) {
  shortMessage: 'Command failed with exit code 1: git push --tags https://github.com/andrewszucs/how-to-create-a-react-lib HEAD:master',
  command: 'git push --tags https://github.com/andrewszucs/how-to-create-a-react-lib HEAD:master',
  exitCode: 1,
  signal: undefined,
  signalDescription: undefined,
  stdout: '',
  stderr: 'remote: error: GH006: Protected branch update failed for refs/heads/master.        \n' +
    'remote: error: Required status check "Test code" is expected. At least 1 approving review is required by reviewers with write access.        \n' +
    'To https://github.com/andrewszucs/how-to-create-a-react-lib\n' +
    ' ! [remote rejected] HEAD -> master (protected branch hook declined)\n' +
    "error: failed to push some refs to 'https://github.com/andrewszucs/how-to-create-a-react-lib'",
  failed: true,
  timedOut: [secure],
  isCanceled: [secure],
  killed: [secure],
  pluginName: '@semantic-release/git'
}

Setting up commitizen

• yarn add -D commitizen
• npx commitizen init cz-conventional-changelog --yarn --dev --exact