- Single quotes, no semi
- Auto fix for formatting (aimed to be used standalone without Prettier)
- Designed to work with TypeScript, JSX, Vue out-of-box
- Lints also for json, yaml, markdown
- Sorted imports, dangling commas
- Reasonable defaults, best practices, only one-line of config
- Respects
.gitignore
by default - ESLint Flat config, compose easily!
- Using ESLint Stylistic
- Style principle: Minimal for reading, stable for diff, consistent
pnpm i -D eslint @merlinalexhjp/eslint-config
With "type": "module"
in package.json
(recommended):
// eslint.config.js
import merlin from '@merlinalexhjp/eslint-config'
export default merlin()
With CJS:
// eslint.config.js
const merlin = require('@merlinalexhjp/eslint-config').default
module.exports = merlin()
Note that
.eslintignore
no longer works in Flat config, see customization for more details.
For example:
{
"scripts": {
"lint": "eslint .",
"lint:fix": "eslint . --fix"
}
}
Install VS Code ESLint extension
Add the following settings to your .vscode/settings.json
:
{
// Enable the ESlint flat config support
"eslint.experimental.useFlatConfig": true,
// Disable the default formatter, use eslint instead
"prettier.enable": false,
"editor.formatOnSave": false,
// Auto fix
"editor.codeActionsOnSave": {
"source.fixAll.eslint": "explicit",
"source.organizeImports": "never"
},
// Silent the stylistic rules in you IDE, but still auto fix them
"eslint.rules.customizations": [
{ "rule": "style/*", "severity": "off" },
{ "rule": "*-indent", "severity": "off" },
{ "rule": "*-spacing", "severity": "off" },
{ "rule": "*-spaces", "severity": "off" },
{ "rule": "*-order", "severity": "off" },
{ "rule": "*-dangle", "severity": "off" },
{ "rule": "*-newline", "severity": "off" },
{ "rule": "*quotes", "severity": "off" },
{ "rule": "*semi", "severity": "off" }
],
// Enable eslint for all supported languages
"eslint.validate": [
"javascript",
"javascriptreact",
"typescript",
"typescriptreact",
"vue",
"html",
"markdown",
"json",
"jsonc",
"yaml"
]
}
Since v1.0, we migrated to ESLint Flat config. It provides much better organization and composition.
Normally you only need to import the merlin
preset:
// eslint.config.js
import merlin from '@merlinalexhjp/eslint-config'
export default merlin()
And that's it! Or you can configure each integration individually, for example:
// eslint.config.js
import merlin from '@merlin/eslint-config'
export default merlin({
// Enable stylistic formatting rules
// stylistic: true,
// Or customize the stylistic rules
stylistic: {
indent: 2, // 4, or 'tab'
quotes: 'single', // or 'double'
},
// TypeScript and Vue are auto-detected, you can also explicitly enable them:
typescript: true,
vue: true,
// Disable jsonc and yaml support
jsonc: false,
yaml: false,
// `.eslintignore` is no longer supported in Flat config, use `ignores` instead
ignores: [
'./fixtures',
// ...globs
]
})
The merlin
factory function also accepts any number of arbitrary custom config overrides:
// eslint.config.js
import merlin from '@merlin/eslint-config'
export default merlin(
{
// Configures for merlin's config
},
// From the second arguments they are ESLint Flat Configs
// you can have multiple configs
{
files: ['**/*.ts'],
rules: {},
},
{
rules: {},
},
)
Certain rules would only be enabled in specific files, for example, ts/*
rules would only be enabled in .ts
files and vue/*
rules would only be enabled in .vue
files. If you want to override the rules, you need to specify the file extension:
// eslint.config.js
import merlin from '@merlinalexhjp/eslint-config'
export default merlin(
{ vue: true, typescript: true },
{
// Remember to specify the file glob here, otherwise it might cause the vue plugin to handle non-vue files
files: ['**/*.vue'],
rules: {
'vue/operator-linebreak': ['error', 'before'],
},
},
{
// Without `files`, they are general rules for all files
rules: {
'style/semi': ['error', 'never'],
},
}
)
We also provided an overrides
options to make it easier:
// eslint.config.js
import merlin from '@merlinalexhjp/eslint-config'
export default merlin({
overrides: {
vue: {
'vue/operator-linebreak': ['error', 'before'],
},
typescript: {
'ts/consistent-type-definitions': ['error', 'interface'],
},
yaml: {},
// ...
}
})
We do include configs for React. But due to the install size of React plugins we didn't include the dependencies by default.
To enable React support, need to explicitly turn it on:
// eslint.config.js
import merlin from '@merlinalexhjp/eslint-config'
export default merlin({
react: true,
})
Running npx eslint
should prompt you to install the required dependencies, otherwise you can install them manually:
npm i -D eslint-plugin-react eslint-plugin-react-hooks eslint-plugin-react-refresh