feat!: initial flat config support

BREAKING CHANGES:
- Dropped legacy `.eslintrc*` support
- Dropped support for Vue 2
- Airbnb and Standard style guides are not yet supported

It satisfies the use case for basic JavaScript / TypeScript projects
with Vue 3.
The formatting of `additionalConfigs` still needs to be improved to be
able to be used in `create-vue`.
The CLI functionality is too basic and needs to be improved.

Author: haoqunjiang

.editorconfig

@@ -0,0 +1,6 @@
+[*.{js,jsx,mjs,cjs,ts,tsx,mts,cts,vue}]
+charset = utf-8
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true

.prettierrc.json

@@ -0,0 +1,6 @@
+{
+  "$schema": "https://json.schemastore.org/prettierrc",
+  "semi": false,
+  "singleQuote": true,
+  "arrowParens": "avoid"
+}

bin/create-eslint-config.js

@@ -5,7 +5,7 @@ import path from 'node:path'
 import process from 'node:process'
 import { bold, blue, yellow, red, green, dim } from 'kolorist'
 
-import createConfig, { deepMerge, CREATE_ALIAS_SETTING_PLACEHOLDER } from '../index.js'
+import createConfig, { deepMerge } from '../index.js'
 
 const require = createRequire(import.meta.url)
 const Enquirer = require('enquirer')
@@ -43,6 +43,7 @@ const pkg = JSON.parse(rawPkgJson)
 
 // 1. check for existing config files
 // `.eslintrc.*`, `eslintConfig` in `package.json`
+// FIXME: `eslint.config.*`
 // ask if wanna overwrite?
 
 // https://eslint.org/docs/latest/user-guide/configuring/configuration-files#configuration-file-formats
@@ -89,55 +90,20 @@ if (pkg.eslintConfig) {
 }
 
 // 2. Check Vue
-// Not detected? Choose from Vue 2 or 3
-// TODO: better support for 2.7 and vue-demi
 let vueVersion
+// Not detected? Abort
+// Vue 2? Abort because this tool only supports Vue 3
 try {
   vueVersion = requireInCwd('vue/package.json').version
   console.info(dim(`Detected Vue.js version: ${vueVersion}`))
 } catch (e) {
-  const anwsers = await prompt({
-    type: 'select',
-    name: 'vueVersion',
-    message: 'Which Vue.js version do you use in the project?',
-    choices: [
-      '3.x',
-      '2.x'
-    ]
-  })
-  vueVersion = anwsers.vueVersion
+  // FIXME: warning that this only support Vue 3
 }
 
-// 3. Choose a style guide
-// - Error Prevention (ESLint Recommended)
-// - Standard
-// - Airbnb
-const { styleGuide } = await prompt({
-  type: 'select',
-  name: 'styleGuide',
-  message: 'Which style guide do you want to follow?',
-  choices: [
-    {
-      name: 'default',
-      message: 'ESLint Recommended (Error-Prevention-Only)'
-    },
-    {
-      name: 'airbnb',
-      message: `Airbnb ${dim('(https://airbnb.io/javascript/)')}`
-    },
-    {
-      name: 'standard',
-      message: `Standard ${dim('(https://standardjs.com/)')}`
-    }
-  ]
-})
-
 // 4. Check TypeScript
 // 4.1 Allow JS?
-// 4.2 Allow JS in Vue?
-// 4.3 Allow JSX (TSX, if answered no in 4.1) in Vue?
+// 4.2 Allow JS in Vue? Allow JSX (TSX, if answered no in 4.1) in Vue?
 let hasTypeScript = false
-const additionalConfig = {}
 try {
   const tsVersion = requireInCwd('typescript/package.json').version
   console.info(dim(`Detected TypeScript version: ${tsVersion}`))
@@ -154,108 +120,54 @@ try {
   hasTypeScript = anwsers.hasTypeScript
 }
 
-// TODO: we don't have more fine-grained sub-rulsets in `@vue/eslint-config-typescript` yet
-if (hasTypeScript && styleGuide !== 'default') {
-  const { allowJsInVue } = await prompt({
-    type: 'toggle',
-    disabled: 'No',
-    enabled: 'Yes',
-    name: 'allowJsInVue',
-    message: `Do you use plain ${yellow('<script>')}s (without ${blue('lang="ts"')}) in ${green('.vue')} files?`,
-    initial: false
-  })
-
-  if (allowJsInVue) {
-    const { allowJsxInVue } = await prompt({
-      type: 'toggle',
-      disabled: 'No',
-      enabled: 'Yes',
-      name: 'allowJsxInVue',
-      message: `Do you use ${yellow('<script lang="jsx">')}s in ${green('.vue')} files (not recommended)?`,
-      initial: false
-    })
-
-    additionalConfig.extends = [
-      `@vue/eslint-config-${styleGuide}-with-typescript/${
-        allowJsxInVue
-          ? 'allow-jsx-in-vue'
-          : 'allow-js-in-vue'
-      }`
-    ]
-  } else {
-    const { allowTsxInVue } = await prompt({
-      type: 'toggle',
-      disabled: 'No',
-      enabled: 'Yes',
-      name: 'allowTsxInVue',
-      message: `Do you use ${yellow('<script lang="tsx">')}s in ${green('.vue')} files (not recommended)?`,
-      initial: false
-    })
-
-    if (allowTsxInVue) {
-      additionalConfig.extends = [
-        `@vue/eslint-config-${styleGuide}-with-typescript/allow-tsx-in-vue`
-      ]
-    }
-  }
-}
-
-// 5. If Airbnb && !TypeScript
-// Does your project use any path aliases?
-// Show [snippet prompts](https://github.com/enquirer/enquirer#snippet-prompt) for the user to input aliases
-if (styleGuide === 'airbnb' && !hasTypeScript) {
-  const { hasAlias } = await prompt({
-    type: 'toggle',
-    disabled: 'No',
-    enabled: 'Yes',
-    name: 'hasAlias',
-    message: 'Does your project use any path aliases?',
-    initial: false
-  })
-
-  if (hasAlias) {
-    console.info()
-    console.info(`Please input your alias configurations (press ${bold(green('<Enter>'))} to skip):`)
-
-    const aliases = {}
-    while (true) {
-      console.info()
-
-      const { prefix } = await prompt({
-        type: 'input',
-        name: 'prefix',
-        message: 'Alias prefix',
-        validate: (val) => {
-          if (Object.hasOwn(aliases, val)) {
-            return red(`${green(val)} has already been aliased to ${green(aliases[val])}`)
-          }
-
-          return true
-        }
-      })
-
-      if (!prefix) {
-        break
-      }
-
-      const { replacement } = await prompt({
-        type: 'input',
-        name: 'replacement',
-        message: `Path replacement for the prefix ${green(prefix)}`,
-        validate: (value) => value !== ''
-      })
-
-      aliases[prefix] = replacement
-    }
-    if (Object.keys(aliases).length > 0) {
-      additionalConfig.settings = { [CREATE_ALIAS_SETTING_PLACEHOLDER]: aliases }
-    }
-
-    console.info()
-  }
-}
-
-// 6. Do you need Prettier to format your codebase?
+const supportedScriptLangs = {}
+// FIXME: Use a multi-select prompt
+// if (hasTypeScript) {
+//   const { allowJsInVue } = await prompt({
+//     type: 'toggle',
+//     disabled: 'No',
+//     enabled: 'Yes',
+//     name: 'allowJsInVue',
+//     message: `Do you use plain ${yellow('<script>')}s (without ${blue('lang="ts"')}) in ${green('.vue')} files?`,
+//     initial: false
+//   })
+
+//   if (allowJsInVue) {
+//     const { allowJsxInVue } = await prompt({
+//       type: 'toggle',
+//       disabled: 'No',
+//       enabled: 'Yes',
+//       name: 'allowJsxInVue',
+//       message: `Do you use ${yellow('<script lang="jsx">')}s in ${green('.vue')} files (not recommended)?`,
+//       initial: false
+//     })
+
+//     additionalConfig.extends = [
+//       `@vue/eslint-config-${styleGuide}-with-typescript/${
+//         allowJsxInVue
+//           ? 'allow-jsx-in-vue'
+//           : 'allow-js-in-vue'
+//       }`
+//     ]
+//   } else {
+//     const { allowTsxInVue } = await prompt({
+//       type: 'toggle',
+//       disabled: 'No',
+//       enabled: 'Yes',
+//       name: 'allowTsxInVue',
+//       message: `Do you use ${yellow('<script lang="tsx">')}s in ${green('.vue')} files (not recommended)?`,
+//       initial: false
+//     })
+
+//     if (allowTsxInVue) {
+//       additionalConfig.extends = [
+//         `@vue/eslint-config-${styleGuide}-with-typescript/allow-tsx-in-vue`
+//       ]
+//     }
+//   }
+// }
+
+// 5. Do you need Prettier to format your codebase?
 const { needsPrettier } = await prompt({
   type: 'toggle',
   disabled: 'No',
@@ -265,30 +177,23 @@ const { needsPrettier } = await prompt({
 })
 
 const { pkg: pkgToExtend, files } = createConfig({
-  vueVersion,
-  styleGuide,
   hasTypeScript,
+  supportedScriptLangs,
   needsPrettier,
-
-  additionalConfig
 })
 
 // TODO:
 // Add `lint` command to package.json
-// - eslint ... (extensions vary based on the language)
-// - note: for Vue CLI, remove the @vue/cli-plugin-eslint and override its lint command, they are too outdated.
 // Add a `format` command to package.json when prettier is used
-// TODO:
-// Add a note about that Vue CLI projects may need a `tsconfig.eslint.json`
 
 deepMerge(pkg, pkgToExtend)
 
 // Write `package.json` back
-writeFileSync(pkgJsonPath, JSON.stringify(pkg, null, indent) + '\n', 'utf-8')
+writeFileSync(pkgJsonPath, JSON.stringify(pkg, null, indent) + '\n', 'utf8')
 // Write files back
 for (const [name, content] of Object.entries(files)) {
   const fullPath = path.resolve(cwd, name)
-  writeFileSync(fullPath, content, 'utf-8')
+  writeFileSync(fullPath, content, 'utf8')
 }
 
 // Prompt: Run `npm install` or `yarn` or `pnpm install`
@@ -300,7 +205,7 @@ const lintCommand = packageManager === 'npm' ? 'npm run lint' : `${packageManage
 
 console.info(
   '\n' +
-  `${bold(yellow('package.json'))} and ${bold(blue('.eslintrc.cjs'))} have been updated.\n` +
+  `${bold(yellow('package.json'))} and ${bold(blue('eslint.config.mjs'))} have been updated.\n` +
   `Now please run ${bold(green(installCommand))} to re-install the dependencies.\n` +
   `Then you can run ${bold(green(lintCommand))} to lint your files.`
 )

eslint.config.js

@@ -0,0 +1,13 @@
+import pluginVue from 'eslint-plugin-vue'
+// Use the TS config here because the default js parser doesn't support import attributes
+import vueTsEslintConfig from '@vue/eslint-config-typescript'
+
+export default [
+  {
+    name: 'app/files-to-lint',
+    files: ['**/*.{js,mjs,jsx,ts,mts,tsx,vue}'],
+    ignores: ['**/dist/**', '**/dist-ssr/**', '**/coverage/**'],
+  },
+  ...pluginVue.configs['flat/essential'],
+  ...vueTsEslintConfig(),
+]