feat: enable typed ESLint rules (@typescript-eslint/recommended + stylistic)

.eslintrc.js

@@ -6,4 +6,59 @@ module.exports = {
     'react-native/sort-styles': 0,
     'react-native/no-inline-styles': 1,
   },
+  overrides: [
+    {
+      files: ['*.ts', '*.tsx'],
+      parser: '@typescript-eslint/parser',
+      plugins: ['@typescript-eslint'],
+      parserOptions: {
+        project: './tsconfig.json',
+        tsconfigRootDir: __dirname,
+      },
+      extends: [
+        'plugin:@typescript-eslint/recommended',
+        'plugin:@typescript-eslint/stylistic',
+      ],
+      rules: {
+        '@typescript-eslint/no-floating-promises': 'warn',
+        '@typescript-eslint/no-misused-promises': 'warn',
+        '@typescript-eslint/await-thenable': 'warn',
+        '@typescript-eslint/strict-boolean-expressions': [
+          'warn',
+          {
+            allowNullableBoolean: true,
+            allowNullableString: true,
+            allowNullableNumber: true,
+            allowNullableObject: true,
+          },
+        ],
+        // `void expr` (including as a concise arrow body, e.g.
+        // `onPress={() => void save()}`) is the idiomatic way to satisfy
+        // no-floating-promises for intentionally unawaited promises, which
+        // conflicts with the base config's blanket ban on `void`.
+        'no-void': 'off',
+      },
+    },
+    {
+      // react-navigation's ParamList generics require an object-literal
+      // `type` alias (not `interface`) to satisfy their implicit index
+      // signature constraint — https://reactnavigation.org/docs/typescript
+      files: ['src/navigation/*.ts', 'src/navigation/*.tsx'],
+      rules: {
+        '@typescript-eslint/consistent-type-definitions': 'off',
+      },
+    },
+    {
+      // @react-native-firebase/messaging is an optional peer dependency
+      // (see .env.example): a static `import` would be resolved by Metro at
+      // bundle time and fail hard when the package or native config is
+      // absent, whereas a synchronous `require()` inside try/catch can be
+      // caught and swapped for a no-op adapter, and is intercepted cleanly
+      // by jest.mock() in tests.
+      files: ['src/services/firebaseMessaging.ts'],
+      rules: {
+        '@typescript-eslint/no-var-requires': 'off',
+      },
+    },
+  ],
 };

App.tsx

@@ -16,16 +16,16 @@ function AppSync() {
   useEffect(() => {
     const sub = AppState.addEventListener('change', (state: AppStateStatus) => {
       if (state === 'active') {
-        syncPendingProofs();
+        void syncPendingProofs();
       }
     });
     return () => sub.remove();
   }, [syncPendingProofs]);
 
   useEffect(() => {
-    registerForPushNotifications().then(token => {
+    void registerForPushNotifications().then(token => {
       if (token) {
-        sendTokenToServer(token);
+        void sendTokenToServer(token);
       }
     });
   }, []);