[Monorepo] Setup linters (#3503)

## Description

This PR sets up `eslint`, `prettier` and `tsc` so that we can finally run lint checks in monorepo.

Each workspace has `ts-check` and `lint-js` scripts which run in given workspace. Running those scripts in `root` results in running them in each workspace. 

> [!NOTE]
> Running those scripts from `root` does not trigger any checks in `ExpoExample` and `MacOSExample`, as they only export app from `CommonApp`

## Test plan

Run `yarn ts-check` and `yarn lint-js` from `root`.

Author: m-bert

.eslintrc.json

@@ -1,4 +1,5 @@
 {
+  "root": true,
   "extends": [
     "plugin:@typescript-eslint/recommended",
     "plugin:@typescript-eslint/recommended-requiring-type-checking",
@@ -15,7 +16,7 @@
     "project": ["./tsconfig.json"]
   },
   "env": { "browser": true, "node": true, "jest/globals": true },
-  "plugins": ["jest"],
+  "plugins": ["react", "jest"],
   "ignorePatterns": ["packages/react-native-gesture-handler/lib/**/*"],
   "rules": {
     // removed in new jest-eslint-plugin, referenced in satya config
@@ -26,19 +27,28 @@
       "warn",
       { "assertFunctionNames": ["expect*", "assert*"] }
     ],
+    "jest/no-conditional-expect": "warn",
+
     // temporary, remove after we type internals better
     "@typescript-eslint/restrict-template-expressions": "warn",
     "@typescript-eslint/no-unsafe-member-access": "warn",
     "@typescript-eslint/no-unsafe-call": "warn",
     "@typescript-eslint/no-unsafe-assignment": "warn",
+    "@typescript-eslint/no-unsafe-argument": "warn",
     "@typescript-eslint/no-unsafe-return": "warn",
+    "@typescript-eslint/no-non-null-assertion": "warn",
     "@typescript-eslint/ban-types": "warn",
 
     // common
     "@typescript-eslint/explicit-module-boundary-types": "off",
     "import/named": "off",
     "react/sort-comp": "off",
     "react/no-unused-prop-types": "warn",
+    "react-hooks/exhaustive-deps": "warn",
+    "@typescript-eslint/no-floating-promises": "warn",
+    "@eslint-react/no-missing-component-display-name": "warn",
+    "@eslint-react/no-nested-components": "warn",
+    "@eslint-react/no-nested-component-definitions": "warn",
     "prefer-const": [
       "error",
       {
@@ -49,6 +59,13 @@
       "error",
       { "argsIgnorePattern": "^_" }
     ],
+    "@typescript-eslint/no-explicit-any": "warn",
+    "@typescript-eslint/no-redundant-type-constituents": "warn",
+    "@typescript-eslint/no-empty-function": "error",
+    "@typescript-eslint/no-misused-promises": "warn",
+    "@eslint-react/no-array-index-key": "warn",
+    "@eslint-react/hooks-extra/no-direct-set-state-in-use-effect": "warn",
+    "@eslint-react/hooks-extra/prefer-use-state-lazy-initialization": "warn",
     "no-redeclare": "off",
     "@typescript-eslint/no-redeclare": "error",
     "no-use-before-define": "off",
@@ -61,6 +78,7 @@
       }
     ],
     "curly": "error",
-    "spaced-comment": "error"
+    "spaced-comment": "error",
+    "no-alert": "warn"
   }
 }

.github/workflows/android-build.yml

@@ -34,7 +34,7 @@ jobs:
           cache: 'yarn'
       - name: Install node dependencies
         working-directory: ${{ matrix.working-directory }}
-        run: yarn install --immutable && yarn postinstall
+        run: yarn install --immutable
       - name: Build app
         working-directory: ${{ matrix.working-directory }}/android
         run: ./gradlew assembleDebug --console=plain -PreactNativeArchitectures=arm64-v8a

.github/workflows/ios-build.yml

@@ -36,7 +36,7 @@ jobs:
           cache: 'yarn'
       - name: Install node dependencies
         working-directory: ${{ matrix.working-directory }}
-        run: yarn install --immutable && yarn postinstall
+        run: yarn install --immutable
       - name: Install pods
         if: ${{ matrix.working-directory == 'apps/BasicExample' }}
         working-directory: ${{ matrix.working-directory }}/ios

.github/workflows/static-example-apps-checks.yml

@@ -26,14 +26,11 @@ jobs:
         with:
           node-version: 18
           cache: 'yarn'
-      - name: Install root node dependencies
-        run: yarn --immutable && yarn prepare
-      - name: Install ${{ matrix.working-directory }} app node dependencies
-        working-directory: ${{ matrix.working-directory }}
-        run: yarn
+      - name: Install node dependencies
+        run: yarn --immutable && yarn postinstall
       - name: Check types
         working-directory: ${{ matrix.working-directory }}
-        run: yarn tsc --noEmit
+        run: yarn ts-check
       - name: Lint
         working-directory: ${{ matrix.working-directory }}
-        run: yarn lint-check
+        run: yarn lint-js

.github/workflows/static-root-checks.yml

@@ -26,13 +26,13 @@ jobs:
           node-version: 18
           cache: 'yarn'
       - name: Install node dependencies
-        run: yarn
+        run: yarn --immutable && yarn postinstall
       - name: Check types
         working-directory: ${{ env.WORKING_DIRECTORY }}
-        run: yarn tsc --noEmit
+        run: yarn ts-check
       - name: Lint
         working-directory: ${{ env.WORKING_DIRECTORY }}
-        run: yarn lint:js-root
+        run: yarn lint-js
       - name: Check for circular dependencies
         working-directory: ${{ env.WORKING_DIRECTORY }}
         run: yarn circular-dependency-check

.lintstagedrc.json

@@ -1,3 +1,6 @@
 {
-  "*.(js|jsx|ts|tsx)": ["yarn eslint", "yarn prettier --write"]
+  "**/*.{ts,tsx}": "yarn format:js",
+  "packages/react-native-gesture-handler/android/**/*.kt": "yarn format:android",
+  "packages/react-native-gesture-handler/apple/**/*.{h,m,mm,cpp}": "yarn format:apple",
+  "packages/react-native-gesture-handler/src/specs/*.ts": "yarn sync-architectures"
 }

apps/BasicExample/.eslintrc.js

@@ -8,7 +8,9 @@
     "lint": "eslint .",
     "start": "react-native start",
     "test": "jest",
-    "postinstall": ""
+    "ts-check": "yarn tsc --noEmit",
+    "lint-js": "eslint --ext '.js,.ts,.tsx' src/ && yarn prettier --check './src/**/*.{js,jsx,ts,tsx}'",
+    "format-js": "prettier --write --list-different './src/**/*.{js,jsx,ts,tsx}'"
   },
   "dependencies": {
     "react": "19.0.0",
@@ -27,13 +29,20 @@
     "@react-native/metro-config": "0.79.0",
     "@react-native/typescript-config": "0.79.0",
     "@types/jest": "^29.5.13",
-    "@types/react": "^19.0.0",
+    "@types/react": "^19.0.12",
     "@types/react-test-renderer": "^19.0.0",
-    "eslint": "^8.19.0",
+    "@typescript-eslint/eslint-plugin": "^6.9.0",
+    "@typescript-eslint/parser": "^6.9.0",
+    "eslint": "^8.57.0",
+    "eslint-config-satya164": "3.3.0",
+    "eslint-import-resolver-babel-module": "^5.2.0",
+    "eslint-plugin-jest": "27.4.3",
+    "eslint-plugin-prettier": "^5.0.1",
+    "eslint-plugin-react": "^7.37.5",
     "jest": "^29.6.3",
-    "prettier": "2.8.8",
+    "prettier": "3.3.3",
     "react-test-renderer": "19.0.0",
-    "typescript": "5.0.4"
+    "typescript": "~5.8.3"
   },
   "engines": {
     "node": ">=18"

apps/BasicExample/package.json

@@ -1,4 +1,3 @@
-/* eslint-disable react-native/no-inline-styles */
 import React, { useEffect, useState } from 'react';
 import { View, Text, Pressable, BackHandler } from 'react-native';
 
@@ -55,7 +54,7 @@ export default class Navigator {
 
   goBack() {
     if (this.history.length === 1) {
-      throw "Can't go back, no history";
+      throw new Error("Can't go back, no history");
     }
     this.history.pop();
     this.setCurrentRoute(this.history[this.history.length - 1]);
@@ -79,6 +78,7 @@ export default class Navigator {
     this.setCurrentRoute = setCurrentRoute;
 
     useEffect(() => {
+      // eslint-disable-next-line @typescript-eslint/unbound-method
       return BackHandler.addEventListener('hardwareBackPress', this.backHandler)
         .remove;
     }, []);