Add eslint plugin to lint unused translation keys

Author: frozenhelium

app/eslint.config.js renamed to app/eslint.config.ts

@@ -1,9 +1,13 @@
+// eslint.config.js
+// @ts-expect-error: @eslint/eslintrc has no types
 import { FlatCompat } from '@eslint/eslintrc';
 import js from '@eslint/js';
 import json from "@eslint/json";
 import tseslint from "typescript-eslint";
 import process from 'process';
 
+import i18nUsage from './scripts/eslint/i18n-usage';
+
 const dirname = process.cwd();
 
 const compat = new FlatCompat({
@@ -33,7 +37,7 @@ const appConfigs = compat.config({
         '@typescript-eslint',
         'react-refresh',
         'simple-import-sort',
-        'import-newlines'
+        'import-newlines',
     ],
     settings: {
         'import/parsers': {
@@ -101,7 +105,9 @@ const appConfigs = compat.config({
         'react/require-default-props': ['warn', { ignoreFunctionalComponents: true }],
         'simple-import-sort/imports': 'warn',
         'simple-import-sort/exports': 'warn',
-        'import-newlines/enforce': ['warn', 1]
+        'import-newlines/enforce': ['warn', 1],
+
+        // 'i18n-usage/ensure-i18n-keys-used': ['warn']
     },
     overrides: [
         {
@@ -128,7 +134,7 @@ const appConfigs = compat.config({
             }
         }
     ]
-}).map((conf) => ({
+}).map((conf: object) => ({
     ...conf,
     files: ['src/**/*.tsx', 'src/**/*.jsx', 'src/**/*.ts', 'src/**/*.js'],
     ignores: [
@@ -139,27 +145,43 @@ const appConfigs = compat.config({
     ],
 }));
 
+const tseslintRecommendedRules = tseslint.configs.recommended.map((conf) => ({
+    ...(conf.rules)
+}));
+
 const otherConfig = {
     files: ['*.js', '*.ts', '*.cjs'],
     ...js.configs.recommended,
-    ...tseslint.configs.recommended,
+    ...tseslintRecommendedRules,
 };
 
 const jsonConfig = {
     files: ['**/*.json'],
     language: 'json/json',
     rules: {
         'json/no-duplicate-keys': 'error',
+        'json/no-empty-keys': 'error',
+        'i18n-usage/ensure-i18n-keys-used': 'warn',
     },
 };
 
+// const i18nJsonConfig = {
+//     files: ['**/i18n.json'],
+//     language: 'json/json',
+//     rules: {
+//         'i18n-usage/ensure-i18n-keys-used': 'warn',
+//     },
+// };
+
 export default [
     {
         plugins: {
             json,
+            'i18n-usage': i18nUsage,
         },
     },
     ...appConfigs,
     otherConfig,
     jsonConfig,
+    // i18nJsonConfig,
 ];

app/package.json

@@ -59,20 +59,22 @@
         "sanitize-html": "^2.10.0"
     },
     "devDependencies": {
-        "@eslint/eslintrc": "^3.1.0",
+        "@eslint/eslintrc": "^3.2.0",
         "@eslint/js": "^9.20.0",
         "@eslint/json": "^0.5.0",
         "@julr/vite-plugin-validate-env": "^1.0.1",
         "@types/file-saver": "^2.0.5",
         "@types/mapbox-gl": "^1.13.0",
-        "@types/node": "^20.11.6",
+        "@types/node": "^20.17.19",
         "@types/papaparse": "^5.3.8",
         "@types/react": "^18.0.28",
         "@types/react-dom": "^18.0.11",
         "@types/sanitize-html": "^2.9.0",
         "@types/yargs": "^17.0.32",
         "@typescript-eslint/eslint-plugin": "^8.11.0",
         "@typescript-eslint/parser": "^8.11.0",
+        "@typescript-eslint/typescript-estree": "^8.43.0",
+        "@typescript-eslint/visitor-keys": "^8.44.0",
         "@vitejs/plugin-react-swc": "^3.5.0",
         "@vitest/coverage-v8": "^1.2.2",
         "autoprefixer": "^10.4.14",
@@ -91,6 +93,7 @@
         "eslint-plugin-simple-import-sort": "^12.1.1",
         "fast-glob": "^3.3.2",
         "happy-dom": "^9.18.3",
+        "jiti": "^2.5.1",
         "openapi-typescript": "6.5.5",
         "postcss": "^8.5.3",
         "postcss-nested": "^7.0.2",