ESLint upgrade to use hermes-eslint

.eslintrc.js

@@ -19,15 +19,15 @@ module.exports = {
 
   plugins: [
     'babel',
-    'flowtype',
+    'ft-flow',
     'jest',
     'no-for-of-loops',
     'no-function-declare-after-return',
     'react',
     'react-internal',
   ],
 
-  parser: 'babel-eslint',
+  parser: 'hermes-eslint',
   parserOptions: {
     ecmaVersion: 9,
     sourceType: 'script',
@@ -36,6 +36,16 @@ module.exports = {
   // We're stricter than the default config, mostly. We'll override a few rules
   // and then enable some React specific ones.
   rules: {
+    'ft-flow/array-style-complex-type': [OFF, 'verbose'],
+    'ft-flow/array-style-simple-type': [OFF, 'verbose'], // TODO should be WARNING
+    'ft-flow/boolean-style': ERROR,
+    'ft-flow/no-dupe-keys': ERROR,
+    'ft-flow/no-primitive-constructor-types': ERROR,
+    'ft-flow/no-types-missing-file-annotation': OFF, // TODO should be ERROR
+    'ft-flow/no-unused-expressions': ERROR,
+    // 'ft-flow/no-weak-types': WARNING,
+    // 'ft-flow/require-valid-file-annotation': ERROR,
+
     'no-cond-assign': OFF,
     'no-constant-condition': OFF,
     'no-control-regex': OFF,
@@ -90,7 +100,7 @@ module.exports = {
     'no-param-reassign': OFF,
     'no-process-env': OFF,
     'no-proto': ERROR,
-    'no-redeclare': WARNING,
+    'no-redeclare': OFF, // TODO should be WARNING?
     'no-return-assign': OFF,
     'no-script-url': ERROR,
     'no-self-compare': WARNING,
@@ -209,8 +219,6 @@ module.exports = {
     'react/require-render-return': OFF,
     'react/sort-comp': OFF,
     'react/sort-prop-types': OFF,
-    'flowtype/define-flow-type': WARNING,
-    'flowtype/use-flow-type': WARNING,
 
     'accessor-pairs': OFF,
     'brace-style': [ERROR, '1tbs'],
@@ -230,7 +238,6 @@ module.exports = {
     'no-restricted-globals': [ERROR].concat(restrictedGlobals),
     'no-restricted-syntax': [ERROR, 'WithStatement'],
     'no-shadow': ERROR,
-    'no-unused-expressions': ERROR,
     'no-unused-vars': [ERROR, {args: 'none'}],
     'no-use-before-define': OFF,
     'no-useless-concat': OFF,
@@ -253,8 +260,6 @@ module.exports = {
     // deal. But I turned it off because loading the plugin causes some obscure
     // syntax error and it didn't seem worth investigating.
     'max-len': OFF,
-    // Prettier forces semicolons in a few places
-    'flowtype/object-type-delimiter': OFF,
 
     // React & JSX
     // Our transforms set this automatically
@@ -345,7 +350,7 @@ module.exports = {
       // We apply these settings to the source files that get compiled.
       // They can use all features including JSX (but shouldn't use `var`).
       files: esNextPaths,
-      parser: 'babel-eslint',
+      parser: 'hermes-eslint',
       parserOptions: {
         ecmaVersion: 8,
         sourceType: 'module',
@@ -433,6 +438,56 @@ module.exports = {
   },
 
   globals: {
+    $Call: 'readonly',
+    $ElementType: 'readonly',
+    $Flow$ModuleRef: 'readonly',
+    $FlowFixMe: 'readonly',
+    $Keys: 'readonly',
+    $NonMaybeType: 'readonly',
+    $PropertyType: 'readonly',
+    $ReadOnly: 'readonly',
+    $ReadOnlyArray: 'readonly',
+    $Shape: 'readonly',
+    AnimationFrameID: 'readonly',
+    Class: 'readonly',
+    ClientRect: 'readonly',
+    CopyInspectedElementPath: 'readonly',
+    DOMHighResTimeStamp: 'readonly',
+    EventListener: 'readonly',
+    Iterable: 'readonly',
+    Iterator: 'readonly',
+    JSONValue: 'readonly',
+    JSResourceReference: 'readonly',
+    MouseEventHandler: 'readonly',
+    PropagationPhases: 'readonly',
+    PropertyDescriptor: 'readonly',
+    React$AbstractComponent: 'readonly',
+    React$Component: 'readonly',
+    React$ComponentType: 'readonly',
+    React$Config: 'readonly',
+    React$Context: 'readonly',
+    React$Element: 'readonly',
+    React$ElementConfig: 'readonly',
+    React$ElementProps: 'readonly',
+    React$ElementRef: 'readonly',
+    React$ElementType: 'readonly',
+    React$Key: 'readonly',
+    React$Node: 'readonly',
+    React$Portal: 'readonly',
+    React$Ref: 'readonly',
+    React$StatelessFunctionalComponent: 'readonly',
+    ReadableStreamController: 'readonly',
+    RequestInfo: 'readonly',
+    RequestOptions: 'readonly',
+    ResponseState: 'readonly',
+    StoreAsGlobal: 'readonly',
+    symbol: 'readonly',
+    SyntheticEvent: 'readonly',
+    SyntheticMouseEvent: 'readonly',
+    Thenable: 'readonly',
+    TimeoutID: 'readonly',
+    WheelEventHandler: 'readonly',
+
     spyOnDev: 'readonly',
     spyOnDevAndProd: 'readonly',
     spyOnProd: 'readonly',

package.json

@@ -49,11 +49,12 @@
     "create-react-class": "^15.6.3",
     "danger": "^9.2.10",
     "error-stack-parser": "^2.0.6",
-    "eslint": "^7.7.0",
+    "eslint": "^8.29.0",
     "eslint-config-prettier": "^6.9.0",
     "eslint-plugin-babel": "^5.3.0",
     "eslint-plugin-eslint-plugin": "^3.5.3",
     "eslint-plugin-flowtype": "^2.25.0",
+    "eslint-plugin-ft-flow": "^2.0.3",
     "eslint-plugin-jest": "^22.15.0",
     "eslint-plugin-no-for-of-loops": "^1.0.0",
     "eslint-plugin-no-function-declare-after-return": "^1.0.0",
@@ -66,6 +67,7 @@
     "glob-stream": "^6.1.0",
     "google-closure-compiler": "^20200517.0.0",
     "gzip-size": "^5.1.1",
+    "hermes-eslint": "^0.9.0",
     "jasmine-check": "^1.0.0-rc.0",
     "jest": "^26.6.3",
     "jest-cli": "^26.6.3",

packages/react-art/src/ReactARTHostConfig.js

@@ -450,6 +450,7 @@ export function preparePortalMount(portalInstance: any): void {
   // noop
 }
 
+// eslint-disable-next-line no-undef
 export function detachDeletedInstance(node: Instance): void {
   // noop
 }
@@ -458,6 +459,7 @@ export function requestPostPaintCallback(callback: (time: number) => void) {
   // noop
 }
 
+// eslint-disable-next-line no-undef
 export function prepareRendererToRender(container: Container): void {
   // noop
 }

packages/react-client/src/forks/ReactFlightClientHostConfig.custom.js

@@ -26,14 +26,14 @@
 declare var $$$hostConfig: any;
 
 export type Response = any;
-export opaque type BundlerConfig = mixed; // eslint-disable-line no-undef
-export opaque type ModuleMetaData = mixed; // eslint-disable-line no-undef
-export opaque type ModuleReference<T> = mixed; // eslint-disable-line no-undef
+export opaque type BundlerConfig = mixed;
+export opaque type ModuleMetaData = mixed;
+export opaque type ModuleReference<T> = mixed; // eslint-disable-line no-unused-vars
 export const resolveModuleReference = $$$hostConfig.resolveModuleReference;
 export const preloadModule = $$$hostConfig.preloadModule;
 export const requireModule = $$$hostConfig.requireModule;
 
-export opaque type Source = mixed; // eslint-disable-line no-undef
+export opaque type Source = mixed;
 
 export type UninitializedModel = string;
 export const parseModel = $$$hostConfig.parseModel;

packages/react-devtools-extensions/flow-typed/jest.js

@@ -1,5 +1,16 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ */
+
 'use strict';
 
+/* eslint-disable no-unused-vars */
+
 type JestMockFn<TArguments: $ReadOnlyArray<*>, TReturn> = {
   (...args: TArguments): TReturn,
   /**
@@ -693,13 +704,11 @@ interface JestExpectType {
    * specific arguments.
    */
   toHaveBeenCalledWith(...args: Array<any>): void;
-  toBeCalledWith(...args: Array<any>): void;
   /**
    * Use .toHaveBeenLastCalledWith to ensure that a mock function was last called
    * with specific arguments.
    */
   toHaveBeenLastCalledWith(...args: Array<any>): void;
-  lastCalledWith(...args: Array<any>): void;
   /**
    * Check that an object has a .length property and it is set to a certain
    * numeric value.

packages/react-devtools-extensions/flow-typed/npm/react-test-renderer_v16.x.x.js

@@ -6,6 +6,8 @@
 
 'use strict';
 
+/* eslint-disable no-unused-vars */
+
 type ReactComponentInstance = React$Component<any>;
 
 type ReactTestRendererJSON = {
@@ -77,7 +79,7 @@ declare module 'react-test-renderer/shallow' {
     static createRenderer(): ShallowRenderer;
     getMountedInstance(): ReactTestInstance;
     getRenderOutput<E: React$Element<any>>(): E;
-    getRenderOutput(): React$Element<any>;
+    getRenderOutput(): React$Element<any>; // eslint-disable-line ft-flow/no-dupe-keys
     render(element: React$Element<any>, context?: any): void;
     unmount(): void;
   }

packages/react-devtools-shared/src/__tests__/profilerChangeDescriptions-test.js

@@ -10,7 +10,7 @@
 describe('Profiler change descriptions', () => {
   let React;
   let legacyRender;
-  let store: Store;
+  let store;
   let utils;
 
   beforeEach(() => {

packages/react-devtools-shared/src/__tests__/profilingHostRoot-test.js

@@ -12,7 +12,7 @@ describe('profiling HostRoot', () => {
   let ReactDOMClient;
   let Scheduler;
   let legacyRender;
-  let store: Store;
+  let store;
   let utils;
   let getEffectDurations;
   let effectDurations;

packages/react-devtools-shell/src/e2e/devtools.js

@@ -1,3 +1,12 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @noflow
+ */
+
 import * as React from 'react';
 import * as ReactDOM from 'react-dom';
 import {createRoot} from 'react-dom/client';

packages/react-devtools-shell/src/multi/devtools.js

@@ -1,3 +1,12 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @noflow
+ */
+
 import * as React from 'react';
 import {createRoot} from 'react-dom/client';
 import {

packages/react-devtools-shell/src/multi/left.js

@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
 import * as React from 'react';
 import {useState} from 'react';
 import {createRoot} from 'react-dom';

packages/react-devtools-shell/src/multi/right.js

@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
 import * as React from 'react';
 import {useLayoutEffect, useRef, useState} from 'react';
 import {render} from 'react-dom';

packages/react-devtools-timeline/src/import-worker/importFile.js

@@ -16,8 +16,6 @@ import preprocessData from './preprocessData';
 import {readInputData} from './readInputData';
 import InvalidProfileError from './InvalidProfileError';
 
-declare var self: DedicatedWorkerGlobalScope;
-
 export async function importFile(file: File): Promise<ImportWorkerOutputData> {
   try {
     const readFile = await readInputData(file);

packages/react-dom-bindings/src/client/ReactDOMSelection.js

@@ -31,10 +31,10 @@ export function getOffsets(outerNode) {
   // catch any error that may otherwise arise. See
   // https://bugzilla.mozilla.org/show_bug.cgi?id=208427
   try {
-    /* eslint-disable no-unused-expressions */
+    /* eslint-disable ft-flow/no-unused-expressions */
     anchorNode.nodeType;
     focusNode.nodeType;
-    /* eslint-enable no-unused-expressions */
+    /* eslint-enable ft-flow/no-unused-expressions */
   } catch (e) {
     return null;
   }

packages/react-dom/src/test-utils/ReactTestUtils.js

@@ -390,7 +390,7 @@ function executeDispatchesInOrder(event) {
  * @param {?object} event Synthetic event to be dispatched.
  * @private
  */
-const executeDispatchesAndRelease = function(event: ReactSyntheticEvent) {
+const executeDispatchesAndRelease = function(event /* ReactSyntheticEvent */) {
   if (event) {
     executeDispatchesInOrder(event);
 
@@ -470,7 +470,7 @@ function shouldPreventMouseEvent(name, type, props) {
  * @param {string} registrationName Name of listener (e.g. `onClick`).
  * @return {?function} The stored callback.
  */
-function getListener(inst: Fiber, registrationName: string) {
+function getListener(inst /* Fiber */, registrationName: string) {
   // TODO: shouldPreventMouseEvent is DOM-specific and definitely should not
   // live here; needs to be moved to a better place soon
   const stateNode = inst.stateNode;

packages/react-native-renderer/fabric.js

@@ -10,7 +10,7 @@
 import type {ReactFabricType} from './src/ReactNativeTypes';
 import * as ReactFabric from './src/ReactFabric';
 // Assert that the exports line up with the type we're going to expose.
-// eslint-disable-next-line no-unused-expressions
+// eslint-disable-next-line ft-flow/no-unused-expressions
 (ReactFabric: ReactFabricType);
 
 export * from './src/ReactFabric';

packages/react-native-renderer/index.js

@@ -10,7 +10,7 @@
 import type {ReactNativeType} from './src/ReactNativeTypes';
 import * as ReactNative from './src/ReactNativeRenderer';
 // Assert that the exports line up with the type we're going to expose.
-// eslint-disable-next-line no-unused-expressions
+// eslint-disable-next-line ft-flow/no-unused-expressions
 (ReactNative: ReactNativeType);
 
 export * from './src/ReactNativeRenderer';

packages/react-native-renderer/src/ReactFabricHostConfig.js

@@ -321,7 +321,6 @@ class ReactFabricHostComponent {
   }
 }
 
-// eslint-disable-next-line no-unused-expressions
 // $FlowFixMe[class-object-subtyping] found when upgrading Flow
 // $FlowFixMe[method-unbinding] found when upgrading Flow
 (ReactFabricHostComponent.prototype: $ReadOnly<{...NativeMethods, ...}>);

packages/react-native-renderer/src/ReactNativeFiberHostComponent.js

@@ -126,7 +126,6 @@ class ReactNativeFiberHostComponent {
   }
 }
 
-// eslint-disable-next-line no-unused-expressions
 // $FlowFixMe[class-object-subtyping] found when upgrading Flow
 // $FlowFixMe[method-unbinding] found when upgrading Flow
 (ReactNativeFiberHostComponent.prototype: $ReadOnly<{...NativeMethods, ...}>);

packages/react-native-renderer/src/__tests__/ResponderEventPlugin-test.internal.js

@@ -1402,7 +1402,6 @@ describe('ResponderEventPlugin', () => {
     class ParentComponent extends React.Component {
       pRef = React.createRef();
       p_P1Ref = React.createRef();
-      p_P1Ref = React.createRef();
       p_P1_C1Ref = React.createRef();
       p_P1_C2Ref = React.createRef();
       p_OneOffRef = React.createRef();

packages/react-reconciler/src/ReactFiberCacheComponent.js

@@ -38,7 +38,7 @@ const AbortControllerLocal: typeof AbortController = enableCache
   : (null: any);
 
 export type Cache = {
-  controller: AbortControllerLocal,
+  controller: AbortController,
   data: Map<() => mixed, mixed>,
   refCount: number,
 };