[Flare] Add RN build step for ReactTypes (#15926)

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

@@ -13,6 +13,7 @@ import type {
   MeasureOnSuccessCallback,
   NativeMethodsMixinType,
   ReactNativeBaseComponentViewConfig,
+  ReactNativeEventResponder,
 } from './ReactNativeTypes';
 import type {ReactEventComponentInstance} from 'shared/ReactTypes';
 
@@ -76,7 +77,7 @@ export type UpdatePayload = Object;
 
 export type TimeoutHandle = TimeoutID;
 export type NoTimeout = -1;
-export type EventResponder = any;
+export type EventResponder = ReactNativeEventResponder;
 
 // TODO: Remove this conditional once all changes have propagated.
 if (registerEventHandler) {

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

@@ -7,7 +7,10 @@
  * @flow
  */
 
-import type {ReactNativeBaseComponentViewConfig} from './ReactNativeTypes';
+import type {
+  ReactNativeBaseComponentViewConfig,
+  ReactNativeEventResponder,
+} from './ReactNativeTypes';
 import type {ReactEventComponentInstance} from 'shared/ReactTypes';
 
 import invariant from 'shared/invariant';
@@ -48,7 +51,7 @@ export type ChildSet = void; // Unused
 
 export type TimeoutHandle = TimeoutID;
 export type NoTimeout = -1;
-export type EventResponder = any;
+export type EventResponder = ReactNativeEventResponder;
 
 const UPDATE_SIGNAL = {};
 if (__DEV__) {

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

@@ -157,3 +157,6 @@ export type ReactFabricType = {
 
   __SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED: SecretInternalsFabricType,
 };
+
+// TODO will be addressed with upcoming React Flare support
+export type ReactNativeEventResponder = any;

packages/shared/ReactTypes.js

@@ -7,6 +7,7 @@
  * @flow
  */
 
+// NOTE: this line is changed in the RN build, see: copyRNShims in packaging.js
 import type {EventResponder} from 'react-reconciler/src/ReactFiberHostConfig';
 
 export type ReactNode =

scripts/rollup/packaging.js

@@ -1,6 +1,12 @@
 'use strict';
 
-const {existsSync, readdirSync, unlinkSync} = require('fs');
+const {
+  existsSync,
+  readdirSync,
+  unlinkSync,
+  readFileSync,
+  writeFileSync,
+} = require('fs');
 const Bundles = require('./bundles');
 const {
   asyncCopyTo,
@@ -87,18 +93,22 @@ async function copyWWWShims() {
 }
 
 async function copyRNShims() {
+  const reactTypesBuildTarget = 'build/react-native/shims/ReactTypes.js';
   await Promise.all([
     // React Native
     asyncCopyTo(`${__dirname}/shims/react-native`, 'build/react-native/shims'),
-    asyncCopyTo(
-      require.resolve('shared/ReactTypes.js'),
-      'build/react-native/shims/ReactTypes.js'
-    ),
+    asyncCopyTo(require.resolve('shared/ReactTypes.js'), reactTypesBuildTarget),
     asyncCopyTo(
       require.resolve('react-native-renderer/src/ReactNativeTypes.js'),
       'build/react-native/shims/ReactNativeTypes.js'
     ),
   ]);
+  // Modify the EventResponder type in ReactTypes
+  const reactTypesSource = readFileSync(reactTypesBuildTarget, 'utf8');
+  const original = `import type {EventResponder} from 'react-reconciler/src/ReactFiberHostConfig';`;
+  const changeTo = `import type {ReactNativeEventResponder as EventResponder} from './ReactNativeTypes';`;
+  const modifiedSource = reactTypesSource.replace(original, changeTo);
+  writeFileSync(reactTypesBuildTarget, modifiedSource);
 }
 
 async function copyAllShims() {