chore: add @typescript-eslint

.eslintrc.js

@@ -0,0 +1,82 @@
+/* eslint-disable @typescript-eslint/naming-convention */
+module.exports = {
+  root: true,
+  env: {
+    mocha: true,
+    browser: true,
+  },
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    project: './tsconfig.lint.json',
+  },
+  settings: {
+    'import/resolver': {
+      typescript: {
+        project: './tsconfig.lint.json',
+      },
+    },
+  },
+  plugins: ['@typescript-eslint'],
+  extends: ['airbnb-base', 'plugin:@typescript-eslint/strict', 'prettier'],
+  rules: {
+    'no-plusplus': 'off',
+    'no-param-reassign': 'off',
+    'prefer-destructuring': 'off',
+    'default-param-last': 'off',
+    'prefer-spread': 'off',
+    'no-continue': 'off',
+    'no-constructor-return': 'off',
+    'consistent-return': 'off',
+
+    'import/extensions': 'off',
+
+    /** @todo consider to replace any with unknown */
+    '@typescript-eslint/no-explicit-any': 'off',
+
+    '@typescript-eslint/no-invalid-void-type': 'off',
+    '@typescript-eslint/no-dynamic-delete': 'off',
+    '@typescript-eslint/no-magic-numbers': 'off',
+    'no-use-before-define': 'off',
+    '@typescript-eslint/no-use-before-define': 'error',
+    'no-shadow': 'off',
+    '@typescript-eslint/no-shadow': 'error',
+    '@typescript-eslint/naming-convention': [
+      'error',
+      {
+        selector: 'default',
+        format: ['camelCase'],
+        leadingUnderscore: 'allow',
+        trailingUnderscore: 'allow',
+      },
+
+      {
+        selector: ['import', 'parameter'],
+        format: ['camelCase', 'PascalCase'],
+      },
+
+      {
+        selector: 'variable',
+        format: ['camelCase', 'UPPER_CASE'],
+        leadingUnderscore: 'allow',
+        trailingUnderscore: 'allow',
+      },
+
+      {
+        selector: 'typeLike',
+        format: ['PascalCase'],
+      },
+
+      {
+        selector: 'interface',
+        format: ['PascalCase'],
+        filter: 'i18n',
+      },
+
+      {
+        selector: 'typeAlias',
+        format: ['PascalCase'],
+        leadingUnderscore: 'allow',
+      },
+    ],
+  },
+};

.npmignore

@@ -6,7 +6,7 @@ assets/
 .babelrc
 .editorconfig
 .eslintignore
-.eslintrc
+.eslintrc.js
 .gitignore
 bower.json
 gulpfile.js
@@ -16,6 +16,7 @@ sample.html
 .codeclimate.yml
 .coveralls.yml
 tsconfig.json
+tsconfig.lint.json
 .prettierignore
 .prettierrc.json
 rollup.config.js

i18next.js

@@ -1789,7 +1789,8 @@
       },
       interpolation: {
         escapeValue: true,
-        format: (value, format, lng, options) => value,
+        /** @type {import('i18next').FormatFunction} */
+        format: value => value,
         prefix: '{{',
         suffix: '}}',
         formatSeparator: ',',

index.d.mts

@@ -36,6 +36,7 @@ export type * from './typescript/t.js';
 
 export interface CustomInstanceExtenstions {}
 
+// eslint-disable-next-line @typescript-eslint/naming-convention
 export interface i18n extends i18nextMod.i18n, CustomInstanceExtenstions {}
 
 declare const i18next: i18n;

index.d.ts

@@ -12,7 +12,6 @@ import type {
   ResourceLanguage,
   TOptions,
 } from './typescript/options.js';
-
 import type { KeyPrefix, TFunction } from './typescript/t.js';
 
 export interface WithT<Ns extends Namespace = DefaultNamespace> {
@@ -32,12 +31,14 @@ export class ResourceStore {
   constructor(data: Resource, options: InitOptions);
 
   public data: Resource;
+
   public options: InitOptions;
 
   /**
    * Gets fired when resources got added or removed
    */
   on(event: 'added' | 'removed', callback: (lng: string, ns: string) => void): void;
+
   /**
    * Remove event listener
    * removes all callback when callback not specified
@@ -92,9 +93,9 @@ export type MultiReadCallback = (err: CallbackError, data: Resource | null | und
  * Can be provided as a singleton or as a prototype constructor (preferred for supporting multiple instances of i18next).
  * For singleton set property `type` to `'backend'` For a prototype constructor set static property.
  */
-export interface BackendModule<TOptions = object> extends Module {
+export interface BackendModule<Options = object> extends Module {
   type: 'backend';
-  init(services: Services, backendOptions: TOptions, i18nextOptions: InitOptions): void;
+  init(services: Services, backendOptions: Options, i18nextOptions: InitOptions): void;
   read(language: string, namespace: string, callback: ReadCallback): void;
   /** Save the missing translation */
   create?(
@@ -136,7 +137,7 @@ export interface LanguageDetectorAsyncModule extends Module {
   /** Set to true to enable async detection */
   async: true;
   init?(services: Services, detectorOptions: object, i18nextOptions: InitOptions): void;
-  /** Must call callback passing detected language or return a Promise*/
+  /** Must call callback passing detected language or return a Promise */
   detect(
     callback: (lng: string | readonly string[] | undefined) => void | undefined,
   ): void | Promise<string | readonly string[] | undefined>;
@@ -218,6 +219,7 @@ export interface CloneOptions extends InitOptions {
 
 export interface CustomInstanceExtenstions {}
 
+// eslint-disable-next-line @typescript-eslint/naming-convention
 export interface i18n extends CustomInstanceExtenstions {
   // Expose parameterized t in the i18next interface hierarchy
   t: TFunction<[DefaultNamespace, ...Exclude<FlatNamespace, DefaultNamespace>[]]>;