Renna Labs' Prettier Config

Pairs well with our ESLint config.

Table of Contents

• Renna Labs' Prettier Config
  • Table of Contents
  • Installation
  • Configurations
    • Default Config
    • Four Spaces Config
  • Editor Integration & Autoformatting
    • VS Code
    • Sublime Text 3
    • Atom
  • Pre-commit Hooks
  • Publishing to npm
  • Enforced Rules

Installation

1. Make sure your project is using a Node version >= 10

2. Install dependencies

   npm install --save-dev @rennalabs/prettier-config prettier@2.x.x
   
   # or
   
   yarn add --dev @rennalabs/prettier-config prettier@2.x.x

3. Create a prettier.config.js file at the root of your project with the following:

   module.exports = require('@rennalabs/prettier-config');

Configurations

We export two ESLint configurations for your usage:

1. Default
2. Four Spaces

Default Config

In your prettier.config.js:

module.exports = require('@rennalabs/prettier-config');

Four Spaces Config

Includes everything in the default config, but replaces the tabWidth rule with 4 spaces instead of 2 spaces.

In your prettier.config.js:

module.exports = require('@rennalabs/prettier-config/four-spaces');

Editor Integration & Autoformatting

VS Code

1. Install the Prettier extension: View → Extensions then find and install Prettier - Code formatter

2. Reload the editor

3. Open your settings JSON file and add the following

   // Format on save with Prettier rules
   "editor.formatOnSave": true,
   // Tell the ESLint plugin to run on save
   "editor.codeActionsOnSave": {
     "source.fixAll.eslint": true
   },
   // Turn off Prettier format on save, use ESLint to format instead
   "[javascript]": {
     "editor.formatOnSave": false
   },
   "eslint.alwaysShowStatus": true,
   // An array of language identifiers specify the files to be validated
   "eslint.options": {
     "extensions": [".html", ".js", ".jsx"]
   },

Sublime Text 3

https://packagecontrol.io/packages/JsPrettier

Atom

https://atom.io/packages/prettier-atom

Pre-commit Hooks

As another line of defense, if you want Prettier to automatically fix your errors on commit, you can use lint-staged with husky.

1. Make sure your npm version is >= 7.0.0

   npm install -g npm@latest

2. Make sure your repo has been initialized with git

   git init --initial-branch=main

3. Install the npm packages

   npm install --save-dev lint-staged husky

4. Set up the package.json stuff

   npm set-script prepare "husky install" && npm run prepare \
     && npm set-script lint-staged "lint-staged" \
     && npx husky add .husky/pre-commit "npm run lint-staged"

5. Then in your package.json add

    "lint-staged": {
      "*.{js,css,json,md}": [
        "prettier --write",
        "git add"
      ]
    }

   If you already have lint-staged running ESLint, just add the prettier step on top of it:

   "lint-staged": {
     "*.{js,css,json,md}": [
       "prettier --write",
       "git add"
     ],
     "*.js": [
       "eslint --fix",
       "git add"
     ]
   }

Publishing to npm

Read npm's docs on How to Update a Package.

1. Checkout and pull the main branch

2. Run the release script to bump the version numbers (the script will create a commit and push up the release branch to GitHub for you)

   ./scripts/release

   Use semantic versioning to choose the appropriate version number.

3. Submit and merge a PR from the release branch into main

4. Make sure you're logged into npm from the command line using npm whoami. If you're not logged in, npm login with the credentials in 1pass

5. npm publish

Enforced Rules

Check out all of Prettier's configuration options.

Print Width

Line wrap at 100 characters.

Tab Width

4 spaces per indentation-level

Tabs

Indent lines with spaces, not tabs.

Semicolons

Always print semicolons at the ends of statements.

const greeting = 'hi';

Quote

Use single quotes instead of double quotes.

const quote = 'single quotes are better';

Trailing Commas

Use trailing commas wherever possible.

const obj = {
    a: 'hi',
    b: 'hey',
};

Bracket Spacing

Print spaces between brackets in object literals.

{
    foo: bar;
}

JSX Brackets

Put the > of a multi-line JSX element at the end of the last line instead of being alone on the next line (does not apply to self closing elements).

<button className="prettier-class" id="prettier-id" onClick={this.handleClick}>
    Click Here
</button>

Arrow Function Parentheses

Omit parens when possible.

x => x;