extract emitPromise from parsers modules to shared parsers-primitives (#34935)

Summary:
This PR is a task from https://github.com/facebook/react-native/issues/34872:
> Extract the content of the case 'Promise' ([Flow](https://github.com/facebook/react-native/blob/b444f0e44e0d8670139acea5f14c2de32c5e2ddc/packages/react-native-codegen/src/parsers/flow/modules/index.js#L90-L97), [TypeScript](https://github.com/facebook/react-native/blob/00b795642a6562fb52d6df12e367b84674994623/packages/react-native-codegen/src/parsers/typescript/modules/index.js#L197-L205)) into a single emitPromise function in the parsers-primitives.js file. Use the new function in the parsers.

Note that this PR should be merged after https://github.com/facebook/react-native/pull/34933

## Changelog

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[Internal] [Changed] - Extract contents of the case 'Promise' into a single emitPromise function inside parsers-primitives

Pull Request resolved: https://github.com/facebook/react-native/pull/34935

Test Plan: I tested using jest and flow commands.

Reviewed By: cipolleschi

Differential Revision: D40257033

Pulled By: cipolleschi

fbshipit-source-id: 0246f43c6b688629e2de1259e7f535c2cf6dd0a4

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

@@ -18,6 +18,7 @@ const {
   emitInt32,
   emitRootTag,
   typeAliasResolution,
+  emitPromise,
 } = require('../parsers-primitives.js');
 
 describe('emitBoolean', () => {
@@ -244,3 +245,73 @@ describe('typeAliasResolution', () => {
     });
   });
 });
+
+describe('emitPromise', () => {
+  const moduleName = 'testModuleName';
+  const language = 'Flow';
+  describe("when typeAnnotation doesn't have exactly one typeParameter", () => {
+    const typeAnnotation = {
+      typeParameters: {
+        params: [1, 2],
+        type: 'TypeParameterInstantiation',
+      },
+      id: {
+        name: 'typeAnnotationName',
+      },
+    };
+    it('throws an IncorrectlyParameterizedGenericParserError error', () => {
+      const nullable = false;
+      expect(() =>
+        emitPromise(moduleName, typeAnnotation, language, nullable),
+      ).toThrow();
+    });
+  });
+
+  describe("when typeAnnotation doesn't 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 = emitPromise(
+          moduleName,
+          typeAnnotation,
+          language,
+          nullable,
+        );
+        const expected = {
+          type: 'NullableTypeAnnotation',
+          typeAnnotation: {
+            type: 'PromiseTypeAnnotation',
+          },
+        };
+
+        expect(result).toEqual(expected);
+      });
+    });
+    describe('when nullable is false', () => {
+      const nullable = false;
+      it('returns non nullable type annotation', () => {
+        const result = emitPromise(
+          moduleName,
+          typeAnnotation,
+          language,
+          nullable,
+        );
+        const expected = {
+          type: 'PromiseTypeAnnotation',
+        };
+
+        expect(result).toEqual(expected);
+      });
+    });
+  });
+});

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

@@ -44,6 +44,7 @@ const {
   emitInt32,
   emitRootTag,
   typeAliasResolution,
+  emitPromise,
 } = require('../../parsers-primitives');
 const {
   MisnamedModuleInterfaceParserError,
@@ -95,15 +96,12 @@ function translateTypeAnnotation(
           return emitRootTag(nullable);
         }
         case 'Promise': {
-          assertGenericTypeAnnotationHasExactlyOneTypeParameter(
+          return emitPromise(
             hasteModuleName,
             typeAnnotation,
             language,
+            nullable,
           );
-
-          return wrapNullable(nullable, {
-            type: 'PromiseTypeAnnotation',
-          });
         }
         case 'Array':
         case '$ReadOnlyArray': {

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

@@ -21,10 +21,15 @@ import type {
   Int32TypeAnnotation,
   ReservedTypeAnnotation,
   ObjectTypeAnnotation,
+  NativeModulePromiseTypeAnnotation,
 } from '../CodegenSchema';
+import type {ParserType} from './errors';
 import type {TypeAliasResolutionStatus} from './utils';
 
-const {wrapNullable} = require('./parsers-commons');
+const {
+  wrapNullable,
+  assertGenericTypeAnnotationHasExactlyOneTypeParameter,
+} = require('./parsers-commons');
 
 function emitBoolean(nullable: boolean): Nullable<BooleanTypeAnnotation> {
   return wrapNullable(nullable, {
@@ -113,6 +118,23 @@ function typeAliasResolution(
   });
 }
 
+function emitPromise(
+  hasteModuleName: string,
+  typeAnnotation: $FlowFixMe,
+  language: ParserType,
+  nullable: boolean,
+): Nullable<NativeModulePromiseTypeAnnotation> {
+  assertGenericTypeAnnotationHasExactlyOneTypeParameter(
+    hasteModuleName,
+    typeAnnotation,
+    language,
+  );
+
+  return wrapNullable(nullable, {
+    type: 'PromiseTypeAnnotation',
+  });
+}
+
 module.exports = {
   emitBoolean,
   emitDouble,
@@ -120,4 +142,5 @@ module.exports = {
   emitNumber,
   emitRootTag,
   typeAliasResolution,
+  emitPromise,
 };

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

@@ -44,6 +44,7 @@ const {
   emitInt32,
   emitRootTag,
   typeAliasResolution,
+  emitPromise,
 } = require('../../parsers-primitives');
 const {
   MisnamedModuleInterfaceParserError,
@@ -207,15 +208,12 @@ function translateTypeAnnotation(
           return emitRootTag(nullable);
         }
         case 'Promise': {
-          assertGenericTypeAnnotationHasExactlyOneTypeParameter(
+          return emitPromise(
             hasteModuleName,
             typeAnnotation,
             language,
+            nullable,
           );
-
-          return wrapNullable(nullable, {
-            type: 'PromiseTypeAnnotation',
-          });
         }
         case 'Array':
         case 'ReadonlyArray': {