This is tutorial of onfiguring eslint, prettier for your project
Make your code great again
- Eslint
First of all we need to install eslint and configs as dev dependencies. You can use your own config, but I will use config from airbnb:
yarn add -D eslint eslint-config-airbnb eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-react
or
npm i -D eslint eslint-config-airbnb eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-react
If you are using typescript then instead of "eslint-config-airbnb" should be "eslint-config-airbnb-typescript". Also there should be added "@typescript-eslint/eslint-plugin" package:
yarn add -D eslint eslint-config-airbnb-typescript @typescript-eslint/eslint-plugin eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-react
or
npm i -D eslint eslint-config-airbnb-typescript eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-react
After this we need to create eslint config file:
.eslintrc.js
module.exports = {
env: {
browser: true,
jest: true,
},
extends: ['airbnb', 'react-app'],
// extends: ['airbnb-typescript', 'react-app'], // if you're using typescript
};
Now we need to add scripts to "package.json" file:
"scripts": {
...
"lint:eslint": "eslint . --ext .ts,.js,.tsx,.jsx",
"lint:eslint:fix": "eslint . --ext .ts,.js,.tsx,.jsx --fix"
}
Note
Use .ts or .tsx extentions if you're using typescript:
- "lint:eslint" script will just run eslint for your files and show errors in console
- "lint:eslint:fix" script will run eslint for your files and fix autofixable errors
- Prettier
Next step is to install prettier. Prettier will be running with eslint. For this we need to add few packages:
yarn add -D prettier eslint-config-prettier eslint-plugin-prettier
or
npm i -D prettier eslint-config-prettier eslint-plugin-prettier
After successful installation we need to create prettier config file:
.prettierrc
{
"singleQuote": true,
"trailingComma": "all",
"jsxBracketSameLine": true,
"printWidth": 80,
"tabWidth": 2,
"useTabs": false,
"semi": true
}
And modify eslint config:
.eslintrc.js
const fs = require('fs');
const path = require('path');
const prettierOptions = JSON.parse(
fs.readFileSync(path.resolve(__dirname, '.prettierrc'), 'utf8'),
);
module.exports = {
env: {
browser: true,
jest: true,
},
extends: ['airbnb-typescript', 'react-app', 'prettier', 'prettier/react'],
// extends: ['airbnb-typescript', 'react-app', 'prettier', 'prettier/react'], // if you're using typescript
plugins: ['prettier'],
rules: {
'prettier/prettier': ['error', prettierOptions],
},
};
The next step will be to add script to "package.json" file:
"scripts": {
...
"prettify": "prettier --write **/*.{ts,tsx,js,jsx,json}"
}
"prettify" script will run prettier for your files and fix all founded errors
- Pre-commit hook
For pre-commit hook we will be using lint-staged. We need install two more packages:
npm i -D lint-staged husky
or
yarn add -D lint-staged husky
Now we need to modify "package.json" file:
package.json
"scripts": {
...
"lint-staged": "lint-staged"
},
"husky": {
"hooks": {
"pre-commit": "lint-staged"
}
},
"lint-staged": {
"*.{ts,tsx,js,jsx}": [
"npm run lint:eslint:fix",
"git add --force"
],
"*.{ts,tsx,js,jsx,json}": [
"npm run prettify",
"git add --force"
]
}
Note
Use .ts or .tsx extentions if you're using typescript
Now lint-staged will try to fix errors before commit and won't allow you to commit changes that contains any errors.
- Integration with VSCode
To show errors on your VSCode editor these extensions:
- prettier - https://marketplace.visualstudio.com/items?itemName=esbenp.prettier-vscode
- eslint - https://marketplace.visualstudio.com/items?itemName=dbaeumer.vscode-eslint
To be able autofix errors on file save you need to change these VSCode settings:
"[javascript]": {
"editor.formatOnSave": false
},
"[typescript]": {
"editor.formatOnSave": false
},
"[javascriptreact]": {
"editor.formatOnSave": false
},
"[typescriptreact]": {
"editor.formatOnSave": false
},
"eslint.autoFixOnSave": true,
"prettier.disableLanguages": ["js", "jsx", "ts", "tsx"],
"eslint.validate": [
"javascript",
"javascriptreact",
{ "language": "typescript", "autoFix": true },
{ "language": "typescriptreact", "autoFix": true }
]
Note
We're disabling prettier because it'll work through eslint
I have been following this tutorial and it says "The setting is deprecated. Use editor.codeActionsOnSave instead with a source.fixAll.eslint member" in .vscode config.
The correct format would be
"editor.codeActionsOnSave": { "source.fixAll.eslint": true }
. See #microsoft/vscode#87227 (comment)