Convert the emitCommonTypes implementation from a switch based implementation to a dictionary based one (#36549)

Summary:
Task from https://github.com/facebook/react-native/issues/34872
> [Codegen 80] Convert the emitCommonTypes implementation from a switch based implementation to a dictionary based one

## Changelog:

[Internal] [Changed] - Convert the emitCommonTypes implementation from a switch based implementation to a dictionary based one

Pull Request resolved: https://github.com/facebook/react-native/pull/36549

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

Reviewed By: NickGerleman

Differential Revision: D44244901

Pulled By: rshest

fbshipit-source-id: 50712724c72aad3bd1dae3e7c381242c4913a236

packages/react-native-codegen/src/parsers/__tests__/parsers-primitives-test.js

@@ -1263,6 +1263,7 @@ describe('emitPartial', () => {
     nullable: boolean,
   ): $FlowFixMe {
     return emitPartial(
+      nullable,
       hasteModuleName,
       typeAnnotation,
       /* types: TypeDeclarationMap */
@@ -1278,7 +1279,6 @@ describe('emitPartial', () => {
       },
       /* cxxOnly: boolean */
       false,
-      nullable,
       parser,
     );
   }
@@ -1494,4 +1494,15 @@ describe('emitCommonTypes', () => {
       expect(result).toEqual(expected);
     });
   });
+
+  describe('when typeAnnotation is invalid', () => {
+    const typeAnnotation = {
+      id: {
+        name: 'InvalidName',
+      },
+    };
+    it('returns null', () => {
+      expect(emitCommonTypesForUnitTest(typeAnnotation, false)).toBeNull();
+    });
+  });
 });

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

@@ -476,6 +476,7 @@ function Visitor(infoMap: {isComponent: boolean, isModule: boolean}): {
 }
 
 function emitPartial(
+  nullable: boolean,
   hasteModuleName: string,
   typeAnnotation: $FlowFixMe,
   types: TypeDeclarationMap,
@@ -483,7 +484,6 @@ function emitPartial(
   enumMap: {...NativeModuleEnumMap},
   tryParse: ParserErrorCapturer,
   cxxOnly: boolean,
-  nullable: boolean,
   parser: Parser,
 ): Nullable<NativeModuleTypeAnnotation> {
   throwIfPartialWithMoreParameter(typeAnnotation);
@@ -524,41 +524,33 @@ function emitCommonTypes(
   const genericTypeAnnotationName =
     parser.nameForGenericTypeAnnotation(typeAnnotation);
 
-  switch (genericTypeAnnotationName) {
-    case 'Stringish': {
-      return emitStringish(nullable);
-    }
-    case 'Int32': {
-      return emitInt32(nullable);
-    }
-    case 'Double': {
-      return emitDouble(nullable);
-    }
-    case 'Float': {
-      return emitFloat(nullable);
-    }
-    case 'UnsafeObject':
-    case 'Object': {
-      return emitGenericObject(nullable);
-    }
-    case '$Partial':
-    case 'Partial': {
-      return emitPartial(
-        hasteModuleName,
-        typeAnnotation,
-        types,
-        aliasMap,
-        enumMap,
-        tryParse,
-        cxxOnly,
-        nullable,
-        parser,
-      );
-    }
-    default: {
-      return null;
-    }
+  const typeMap = {
+    Stringish: emitStringish,
+    Int32: emitInt32,
+    Double: emitDouble,
+    Float: emitFloat,
+    UnsafeObject: emitGenericObject,
+    Object: emitGenericObject,
+    $Partial: emitPartial,
+    Partial: emitPartial,
+  };
+
+  const emitter = typeMap[genericTypeAnnotationName];
+  if (!emitter) {
+    return null;
   }
+
+  return emitter(
+    nullable,
+    hasteModuleName,
+    typeAnnotation,
+    types,
+    aliasMap,
+    enumMap,
+    tryParse,
+    cxxOnly,
+    parser,
+  );
 }
 
 module.exports = {