chore: migrate to eslint 9 flat config and format the codebase

electron.vite.config.ts

@@ -10,16 +10,16 @@ export default defineConfig({
         '@/lib': resolve('src/main/lib'),
         '@/classes': resolve('src/main/classes'),
         '@shared': resolve('src/shared'),
-      }
-    }
+      },
+    },
   },
   preload: {
     plugins: [externalizeDepsPlugin()],
     resolve: {
       alias: {
-        '@shared': resolve('src/shared')
-      }
-    }
+        '@shared': resolve('src/shared'),
+      },
+    },
   },
   renderer: {
     assetsInclude: ['src/renderer/public/**/*'],
@@ -31,9 +31,9 @@ export default defineConfig({
         '@/assets': resolve('src/renderer/src/assets'),
         '@/pages': resolve('src/renderer/src/pages'),
         '@/components': resolve('src/renderer/src/components'),
-        '@/utils': resolve('src/renderer/src/utils')
-      }
+        '@/utils': resolve('src/renderer/src/utils'),
+      },
     },
-    plugins: [react()]
-  }
+    plugins: [react()],
+  },
 })

eslint.config.mjs

@@ -0,0 +1,69 @@
+import js from '@eslint/js'
+import globals from 'globals'
+import tseslint from '@electron-toolkit/eslint-config-ts'
+import eslintConfigPrettier from '@electron-toolkit/eslint-config-prettier'
+import react from 'eslint-plugin-react'
+import reactHooks from 'eslint-plugin-react-hooks'
+
+export default tseslint.config(
+  {
+    ignores: ['node_modules/**', 'dist/**', 'out/**'],
+  },
+  js.configs.recommended,
+  tseslint.configs.recommended,
+  {
+    files: ['**/*.{js,jsx,cjs,mjs,ts,tsx,cts,mts}'],
+    languageOptions: {
+      ecmaVersion: 'latest',
+      sourceType: 'module',
+      globals: {
+        ...globals.browser,
+        ...globals.node,
+        ...globals.es2021,
+        ...globals.jest,
+      },
+    },
+    rules: {
+      'no-prototype-builtins': 'off',
+      'no-case-declarations': 'off',
+      'no-useless-escape': 'off',
+      // Backend payloads and theme tokens are snake_case by contract, so this
+      // rule only ever fires on identifiers we are not free to rename.
+      camelcase: 'off',
+      // The `/` marker keeps `--fix` from mangling TypeScript triple-slash
+      // directives (`/// <reference ... />`) into `// / <reference ... />`.
+      'spaced-comment': ['error', 'always', { markers: ['/'] }],
+      'no-duplicate-imports': 'error',
+      '@typescript-eslint/explicit-function-return-type': 'off',
+      '@typescript-eslint/no-unused-vars': 'warn',
+      '@typescript-eslint/no-explicit-any': 'warn',
+      '@typescript-eslint/no-this-alias': 'warn',
+      '@typescript-eslint/ban-ts-comment': 'warn',
+      '@typescript-eslint/no-require-imports': 'warn',
+    },
+  },
+  // React rules apply to the renderer only. The main process has helpers named
+  // `use*` (useNethVoiceAPI, useLogin) that are plain functions, not hooks, and
+  // rules-of-hooks flags them when it is allowed to see them.
+  {
+    files: ['src/renderer/**/*.{js,jsx,ts,tsx}'],
+    ...react.configs.flat.recommended,
+    settings: { react: { version: 'detect' } },
+  },
+  {
+    files: ['src/renderer/**/*.{js,jsx,ts,tsx}'],
+    ...react.configs.flat['jsx-runtime'],
+  },
+  {
+    files: ['src/renderer/**/*.{js,jsx,ts,tsx}'],
+    plugins: { 'react-hooks': reactHooks },
+    rules: {
+      ...reactHooks.configs.recommended.rules,
+      // TypeScript already checks component props.
+      'react/prop-types': 'off',
+      'react/react-in-jsx-scope': 'off',
+      'react/display-name': 'off',
+    },
+  },
+  eslintConfigPrettier,
+)