- Extract the content into handleEventHandler (#38805)

Summary:
Part of https://github.com/facebook/react-native/issues/34872
> Extract the content of the if branches that handle the EventHandlers ([Flow](https://github.com/facebook/react-native/blob/e133100721939108b0f28dfa9f60ac627c804018/packages/react-native-codegen/src/parsers/flow/components/events.js#L131-L151), [TypeScript](https://github.com/facebook/react-native/blob/e133100721939108b0f28dfa9f60ac627c804018/packages/react-native-codegen/src/parsers/typescript/components/events.js#L150-L171)) into a handleEventHandler function in parsers-commons.js. This will take a name, a typeAnnotation, a parser and a findEventArgumentsAndType function as parameters. Use the switch based approach from TypeScript.

## Changelog:

[Internal][Changed]: Extract the content into handleEventHandler

Pull Request resolved: https://github.com/facebook/react-native/pull/38805

Test Plan: `yarn test react-native-codegen`

Reviewed By: rshest

Differential Revision: D48100350

Pulled By: cipolleschi

fbshipit-source-id: 5de6deacd50e87ea0ec96147fff7c14ba55e5368

packages/react-native-codegen/src/parsers/flow/components/events.js

@@ -16,6 +16,7 @@ import type {
   EventTypeAnnotation,
 } from '../../../CodegenSchema.js';
 import type {Parser} from '../../parser';
+import type {EventArgumentReturnType} from '../../parsers-commons';
 
 const {
   throwIfEventHasNoName,
@@ -25,6 +26,7 @@ const {
 const {
   getEventArgument,
   buildPropertiesForEvent,
+  handleEventHandler,
 } = require('../../parsers-commons');
 const {
   emitBoolProp,
@@ -178,11 +180,7 @@ function findEventArgumentsAndType(
   types: TypeMap,
   bubblingType: void | 'direct' | 'bubble',
   paperName: ?$FlowFixMe,
-): {
-  argumentProps: $FlowFixMe,
-  bubblingType: ?('direct' | 'bubble'),
-  paperTopLevelNameDeprecated: ?$FlowFixMe,
-} {
+): EventArgumentReturnType {
   throwIfEventHasNoName(typeAnnotation, parser);
   const name = parser.getTypeAnnotationName(typeAnnotation);
   if (name === '$ReadOnly') {
@@ -192,25 +190,12 @@ function findEventArgumentsAndType(
       bubblingType,
     };
   } else if (name === 'BubblingEventHandler' || name === 'DirectEventHandler') {
-    const eventType = name === 'BubblingEventHandler' ? 'bubble' : 'direct';
-    const paperTopLevelNameDeprecated =
-      parser.getPaperTopLevelNameDeprecated(typeAnnotation);
-    if (
-      typeAnnotation.typeParameters.params[0].type ===
-      parser.nullLiteralTypeAnnotation
-    ) {
-      return {
-        argumentProps: [],
-        bubblingType: eventType,
-        paperTopLevelNameDeprecated,
-      };
-    }
-    return findEventArgumentsAndType(
+    return handleEventHandler(
+      name,
+      typeAnnotation,
       parser,
-      typeAnnotation.typeParameters.params[0],
       types,
-      eventType,
-      paperTopLevelNameDeprecated,
+      findEventArgumentsAndType,
     );
   } else if (types[name]) {
     return findEventArgumentsAndType(

packages/react-native-codegen/src/parsers/parsers-commons.js

@@ -87,6 +87,12 @@ type ExtendedPropResult = {
   knownTypeName: 'ReactNativeCoreViewProps',
 } | null;
 
+export type EventArgumentReturnType = {
+  argumentProps: ?$ReadOnlyArray<$FlowFixMe>,
+  paperTopLevelNameDeprecated: ?$FlowFixMe,
+  bubblingType: ?'direct' | 'bubble',
+};
+
 function wrapModuleSchema(
   nativeModuleSchema: NativeModuleSchema,
   hasteModuleName: string,
@@ -1083,6 +1089,42 @@ function verifyPropNotAlreadyDefined(
   }
 }
 
+function handleEventHandler(
+  name: 'BubblingEventHandler' | 'DirectEventHandler',
+  typeAnnotation: $FlowFixMe,
+  parser: Parser,
+  types: TypeDeclarationMap,
+  findEventArgumentsAndType: (
+    parser: Parser,
+    typeAnnotation: $FlowFixMe,
+    types: TypeDeclarationMap,
+    bubblingType: void | 'direct' | 'bubble',
+    paperName: ?$FlowFixMe,
+  ) => EventArgumentReturnType,
+): EventArgumentReturnType {
+  const eventType = name === 'BubblingEventHandler' ? 'bubble' : 'direct';
+  const paperTopLevelNameDeprecated =
+    parser.getPaperTopLevelNameDeprecated(typeAnnotation);
+
+  switch (typeAnnotation.typeParameters.params[0].type) {
+    case parser.nullLiteralTypeAnnotation:
+    case parser.undefinedLiteralTypeAnnotation:
+      return {
+        argumentProps: [],
+        bubblingType: eventType,
+        paperTopLevelNameDeprecated,
+      };
+    default:
+      return findEventArgumentsAndType(
+        parser,
+        typeAnnotation.typeParameters.params[0],
+        types,
+        eventType,
+        paperTopLevelNameDeprecated,
+      );
+  }
+}
+
 module.exports = {
   wrapModuleSchema,
   unwrapNullable,
@@ -1111,4 +1153,5 @@ module.exports = {
   getTypeResolutionStatus,
   buildPropertiesForEvent,
   verifyPropNotAlreadyDefined,
+  handleEventHandler,
 };

packages/react-native-codegen/src/parsers/typescript/components/events.js

@@ -27,6 +27,7 @@ const {
 const {
   getEventArgument,
   buildPropertiesForEvent,
+  handleEventHandler,
 } = require('../../parsers-commons');
 const {
   emitBoolProp,
@@ -204,27 +205,13 @@ function findEventArgumentsAndType(
       paperName,
     );
   } else if (name === 'BubblingEventHandler' || name === 'DirectEventHandler') {
-    const eventType = name === 'BubblingEventHandler' ? 'bubble' : 'direct';
-    const paperTopLevelNameDeprecated =
-      parser.getPaperTopLevelNameDeprecated(typeAnnotation);
-
-    switch (typeAnnotation.typeParameters.params[0].type) {
-      case parser.nullLiteralTypeAnnotation:
-      case parser.undefinedLiteralTypeAnnotation:
-        return {
-          argumentProps: [],
-          bubblingType: eventType,
-          paperTopLevelNameDeprecated,
-        };
-      default:
-        return findEventArgumentsAndType(
-          parser,
-          typeAnnotation.typeParameters.params[0],
-          types,
-          eventType,
-          paperTopLevelNameDeprecated,
-        );
-    }
+    return handleEventHandler(
+      name,
+      typeAnnotation,
+      parser,
+      types,
+      findEventArgumentsAndType,
+    );
   } else if (types[name]) {
     let elementType = types[name];
     if (elementType.type === 'TSTypeAliasDeclaration') {