feat: introduce type options, enable `ts/explicit-function-return-t…

…ype` for `lib`

README.md

@@ -172,6 +172,9 @@ And that's it! Or you can configure each integration individually, for example:
 import antfu from '@antfu/eslint-config'
 
 export default antfu({
+// Type of the project. 'lib' for libraries, the default is 'app'
+  type: 'lib',
+
   // Enable stylistic formatting rules
   // stylistic: true,
 
@@ -181,7 +184,7 @@ export default antfu({
     quotes: 'single', // or 'double'
   },
 
-  // TypeScript and Vue are auto-detected, you can also explicitly enable them:
+  // TypeScript and Vue are autoetected, you can also explicitly enable them:
   typescript: true,
   vue: true,
 

eslint.config.ts

@@ -11,6 +11,7 @@ export default antfu(
     astro: true,
     typescript: true,
     formatters: true,
+    type: 'lib',
   },
   {
     ignores: [

src/cli/index.ts

@@ -6,7 +6,7 @@ import * as p from '@clack/prompts'
 import { run } from './run'
 import { pkgJson } from './constants'
 
-function header() {
+function header(): void {
   // eslint-disable-next-line no-console
   console.log('\n')
   p.intro(`${c.green(`@antfu/eslint-config `)}${c.dim(`v${pkgJson.version}`)}`)

src/cli/run.ts

@@ -27,7 +27,7 @@ export interface CliRunOptions {
   extra?: string[]
 }
 
-export async function run(options: CliRunOptions = {}) {
+export async function run(options: CliRunOptions = {}): Promise<void> {
   const argSkipPrompt = !!process.env.SKIP_PROMPT || options.yes
   const argTemplate = <FrameworkOption[]>options.frameworks?.map(m => m.trim())
   const argExtra = <ExtraLibrariesOption[]>options.extra?.map(m => m.trim())

src/cli/stages/update-eslint-files.ts

@@ -10,7 +10,7 @@ import parse from 'parse-gitignore'
 import { getEslintConfigContent } from '../utils'
 import type { PromptResult } from '../types'
 
-export async function updateEslintFiles(result: PromptResult) {
+export async function updateEslintFiles(result: PromptResult): Promise<void> {
   const cwd = process.cwd()
   const pathESLintIgnore = path.join(cwd, '.eslintignore')
   const pathPackageJSON = path.join(cwd, 'package.json')

src/cli/stages/update-package-json.ts

@@ -7,7 +7,7 @@ import * as p from '@clack/prompts'
 import { dependenciesMap, pkgJson } from '../constants'
 import type { ExtraLibrariesOption, PromptResult } from '../types'
 
-export async function updatePackageJson(result: PromptResult) {
+export async function updatePackageJson(result: PromptResult): Promise<void> {
   const cwd = process.cwd()
 
   const pathPackageJSON = path.join(cwd, 'package.json')

src/cli/utils.ts

@@ -1,6 +1,6 @@
 import { execSync } from 'node:child_process'
 
-export function isGitClean() {
+export function isGitClean(): boolean {
   try {
     execSync('git diff-index --quiet HEAD --')
     return true
@@ -13,7 +13,7 @@ export function isGitClean() {
 export function getEslintConfigContent(
   mainConfig: string,
   additionalConfigs?: string[],
-) {
+): string {
   return `
 import antfu from '@antfu/eslint-config'
 

src/configs/test.ts

@@ -52,6 +52,8 @@ export async function test(
         'test/prefer-hooks-in-order': 'error',
         'test/prefer-lowercase-title': 'error',
 
+        'ts/explicit-function-return-type': 'off',
+
         ...overrides,
       },
     },

src/configs/typescript.ts

@@ -1,16 +1,17 @@
 import process from 'node:process'
 import { GLOB_ASTRO_TS, GLOB_MARKDOWN, GLOB_TS, GLOB_TSX } from '../globs'
-import type { OptionsComponentExts, OptionsFiles, OptionsOverrides, OptionsTypeScriptParserOptions, OptionsTypeScriptWithTypes, TypedFlatConfigItem } from '../types'
+import type { OptionsComponentExts, OptionsFiles, OptionsOverrides, OptionsProjectType, OptionsTypeScriptParserOptions, OptionsTypeScriptWithTypes, TypedFlatConfigItem } from '../types'
 import { pluginAntfu } from '../plugins'
 import { interopDefault, renameRules } from '../utils'
 
 export async function typescript(
-  options: OptionsFiles & OptionsComponentExts & OptionsOverrides & OptionsTypeScriptWithTypes & OptionsTypeScriptParserOptions = {},
+  options: OptionsFiles & OptionsComponentExts & OptionsOverrides & OptionsTypeScriptWithTypes & OptionsTypeScriptParserOptions & OptionsProjectType = {},
 ): Promise<TypedFlatConfigItem[]> {
   const {
     componentExts = [],
     overrides = {},
     parserOptions = {},
+    type = 'app',
   } = options
 
   const files = options.files ?? [
@@ -123,7 +124,11 @@ export async function typescript(
         'no-useless-constructor': 'off',
         'ts/ban-ts-comment': ['error', { 'ts-expect-error': 'allow-with-description' }],
         'ts/consistent-type-definitions': ['error', 'interface'],
-        'ts/consistent-type-imports': ['error', { disallowTypeAnnotations: false, prefer: 'type-imports' }],
+        'ts/consistent-type-imports': ['error', {
+          disallowTypeAnnotations: false,
+          prefer: 'type-imports',
+        }],
+
         'ts/method-signature-style': ['error', 'property'], // https://www.totaltypescript.com/method-shorthand-syntax-considered-harmful
         'ts/no-dupe-class-members': 'error',
         'ts/no-dynamic-delete': 'off',
@@ -143,6 +148,17 @@ export async function typescript(
         'ts/prefer-ts-expect-error': 'error',
         'ts/triple-slash-reference': 'off',
         'ts/unified-signatures': 'off',
+
+        ...(type === 'lib'
+          ? {
+              'ts/explicit-function-return-type': ['error', {
+                allowExpressions: true,
+                allowHigherOrderFunctions: true,
+                allowIIFEs: true,
+              }],
+            }
+          : {}
+        ),
         ...overrides,
       },
     },

src/factory.ts

@@ -33,6 +33,7 @@ import {
 import { interopDefault } from './utils'
 import { formatters } from './configs/formatters'
 import { regexp } from './configs/regexp'
+import type { RuleOptions } from './typegen'
 
 const flatConfigProps: (keyof TypedFlatConfigItem)[] = [
   'name',
@@ -155,6 +156,7 @@ export function antfu(
       ...typescriptOptions,
       componentExts,
       overrides: getOverrides(options, 'typescript'),
+      type: options.type,
     }))
   }
 
@@ -308,7 +310,7 @@ export function resolveSubOptions<K extends keyof OptionsConfig>(
 export function getOverrides<K extends keyof OptionsConfig>(
   options: OptionsConfig,
   key: K,
-) {
+): Partial<Linter.RulesRecord & RuleOptions> {
   const sub = resolveSubOptions(options, key)
   return {
     ...(options.overrides as any)?.[key],

src/types.ts

@@ -170,6 +170,15 @@ export interface OptionsOverrides {
   overrides?: TypedFlatConfigItem['rules']
 }
 
+export interface OptionsProjectType {
+  /**
+   * Type of the project. `lib` will enable more strict rules for libraries.
+   *
+   * @default 'app'
+   */
+  type?: 'app' | 'lib'
+}
+
 export interface OptionsRegExp {
   /**
    * Override rulelevels
@@ -194,7 +203,7 @@ export interface OptionsUnoCSS extends OptionsOverrides {
   strict?: boolean
 }
 
-export interface OptionsConfig extends OptionsComponentExts {
+export interface OptionsConfig extends OptionsComponentExts, OptionsProjectType {
   /**
    * Enable gitignore support.
    *

src/utils.ts

@@ -49,7 +49,10 @@ export async function combine(...configs: Awaitable<TypedFlatConfigItem | TypedF
  * }]
  * ```
  */
-export function renameRules(rules: Record<string, any>, map: Record<string, string>) {
+export function renameRules(
+  rules: Record<string, any>,
+  map: Record<string, string>,
+): Record<string, any> {
   return Object.fromEntries(
     Object.entries(rules)
       .map(([key, value]) => {
@@ -104,7 +107,7 @@ export async function interopDefault<T>(m: Awaitable<T>): Promise<T extends { de
   return (resolved as any).default || resolved
 }
 
-export async function ensurePackages(packages: (string | undefined)[]) {
+export async function ensurePackages(packages: (string | undefined)[]): Promise<void> {
   if (process.env.CI || process.stdout.isTTY === false)
     return