feat: Extract case Array and ReadOnlyArray into a single emitArrayType function (#35546)

Summary:
This PR extracts the content of the codegen case `'Array'` and `'ReadOnlyArray'` into a single `emitArrayType` function inside the `parsers-primitives.js` file and uses it in both Flow and TypeScript parsers as requested on https://github.com/facebook/react-native/issues/34872. This also adds unit tests to the new `emitArrayType` function.

## Changelog

[Internal] [Changed]  - Extract the content of the case 'Array' and 'ReadOnlyArray'  into a single emitArrayType function

Pull Request resolved: https://github.com/facebook/react-native/pull/35546

Test Plan:
Run `yarn jest react-native-codegen` and ensure CI is green

![image](https://user-images.githubusercontent.com/11707729/205375599-3bbf02bf-85b5-41e6-ae77-fc6e12bee538.png)

Reviewed By: christophpurrer

Differential Revision: D41700084

Pulled By: rshest

fbshipit-source-id: 4bfd2d3ab3f1343bb401ba9c278dc0e0e1ea0989

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

@@ -14,6 +14,7 @@
 import type {UnionTypeAnnotationMemberType} from '../../CodegenSchema';
 
 const {
+  emitArrayType,
   emitBoolean,
   emitDouble,
   emitFloat,
@@ -912,3 +913,86 @@ describe('emitUnion', () => {
     });
   });
 });
+
+describe('emitArrayType', () => {
+  const hasteModuleName = 'SampleTurboModule';
+
+  function emitArrayTypeForUnitTest(
+    typeAnnotation: $FlowFixMe,
+    nullable: boolean,
+  ): $FlowFixMe {
+    return emitArrayType(
+      hasteModuleName,
+      typeAnnotation,
+      parser,
+      /* types: TypeDeclarationMap */
+      {},
+      /* aliasMap: {...NativeModuleAliasMap} */
+      {},
+      /* cxxOnly: boolean */
+      false,
+      nullable,
+      /* the translateTypeAnnotation function */
+      (_, elementType) => elementType,
+    );
+  }
+
+  describe("when typeAnnotation doesn't have exactly one typeParameter", () => {
+    const nullable = false;
+    const typeAnnotation = {
+      typeParameters: {
+        params: [1, 2],
+        type: 'TypeParameterInstantiation',
+      },
+      id: {
+        name: 'typeAnnotationName',
+      },
+    };
+
+    it('throws an IncorrectlyParameterizedGenericParserError error', () => {
+      expect(() =>
+        emitArrayTypeForUnitTest(typeAnnotation, nullable),
+      ).toThrow();
+    });
+  });
+
+  describe('when typeAnnotation has exactly one typeParameter', () => {
+    const typeAnnotation = {
+      typeParameters: {
+        params: [1],
+        type: 'TypeParameterInstantiation',
+      },
+      id: {
+        name: 'typeAnnotationName',
+      },
+    };
+
+    describe('when nullable is true', () => {
+      const nullable = true;
+      it('returns nullable type annotation', () => {
+        const result = emitArrayTypeForUnitTest(typeAnnotation, nullable);
+        const expected = {
+          type: 'NullableTypeAnnotation',
+          typeAnnotation: {
+            type: 'ArrayTypeAnnotation',
+            elementType: 1,
+          },
+        };
+
+        expect(result).toEqual(expected);
+      });
+    });
+    describe('when nullable is false', () => {
+      const nullable = false;
+      it('returns non nullable type annotation', () => {
+        const result = emitArrayTypeForUnitTest(typeAnnotation, nullable);
+        const expected = {
+          type: 'ArrayTypeAnnotation',
+          elementType: 1,
+        };
+
+        expect(result).toEqual(expected);
+      });
+    });
+  });
+});

packages/react-native-codegen/src/parsers/flow/modules/index.js

@@ -32,6 +32,7 @@ const {
   buildPropertySchema,
 } = require('../../parsers-commons');
 const {
+  emitArrayType,
   emitBoolean,
   emitDouble,
   emitFloat,
@@ -106,21 +107,14 @@ function translateTypeAnnotation(
         }
         case 'Array':
         case '$ReadOnlyArray': {
-          assertGenericTypeAnnotationHasExactlyOneTypeParameter(
+          return emitArrayType(
             hasteModuleName,
             typeAnnotation,
             parser,
-          );
-
-          return translateArrayTypeAnnotation(
-            hasteModuleName,
             types,
             aliasMap,
             cxxOnly,
-            typeAnnotation.type,
-            typeAnnotation.typeParameters.params[0],
             nullable,
-            language,
             translateTypeAnnotation,
           );
         }

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

@@ -333,7 +333,37 @@ function translateArrayTypeAnnotation(
   }
 }
 
+function emitArrayType(
+  hasteModuleName: string,
+  typeAnnotation: $FlowFixMe,
+  parser: Parser,
+  types: TypeDeclarationMap,
+  aliasMap: {...NativeModuleAliasMap},
+  cxxOnly: boolean,
+  nullable: boolean,
+  translateTypeAnnotation: $FlowFixMe,
+): Nullable<NativeModuleTypeAnnotation> {
+  assertGenericTypeAnnotationHasExactlyOneTypeParameter(
+    hasteModuleName,
+    typeAnnotation,
+    parser,
+  );
+
+  return translateArrayTypeAnnotation(
+    hasteModuleName,
+    types,
+    aliasMap,
+    cxxOnly,
+    typeAnnotation.type,
+    typeAnnotation.typeParameters.params[0],
+    nullable,
+    parser.language(),
+    translateTypeAnnotation,
+  );
+}
+
 module.exports = {
+  emitArrayType,
   emitBoolean,
   emitDouble,
   emitFloat,

packages/react-native-codegen/src/parsers/typescript/modules/index.js

@@ -26,13 +26,13 @@ const {visit, isModuleRegistryCall, verifyPlatforms} = require('../../utils');
 const {resolveTypeAnnotation, getTypes} = require('../utils.js');
 
 const {
-  assertGenericTypeAnnotationHasExactlyOneTypeParameter,
   parseObjectProperty,
   translateDefault,
   buildPropertySchema,
 } = require('../../parsers-commons');
 
 const {
+  emitArrayType,
   emitBoolean,
   emitDouble,
   emitFloat,
@@ -145,21 +145,14 @@ function translateTypeAnnotation(
         }
         case 'Array':
         case 'ReadonlyArray': {
-          assertGenericTypeAnnotationHasExactlyOneTypeParameter(
+          return emitArrayType(
             hasteModuleName,
             typeAnnotation,
             parser,
-          );
-
-          return translateArrayTypeAnnotation(
-            hasteModuleName,
             types,
             aliasMap,
             cxxOnly,
-            typeAnnotation.type,
-            typeAnnotation.typeParameters.params[0],
             nullable,
-            language,
             translateTypeAnnotation,
           );
         }