Replace ternary in assertGenericTypeAnnotationHasExactlyOneTypeParame…

…ter with typeParameterInstantiation attribute in parser (facebook#35157)

Summary:
Part of facebook#34872:
> Create a new function typeParameterInstantiation in the [parsers.js file](https://github.com/facebook/react-native/blob/main/packages/react-native-codegen/src/parsers/parser.js) and add documentation to it. Implement it properly in the [FlowParser.js](https://github.com/facebook/react-native/blob/main/packages/react-native-codegen/src/parsers/flow/parser.js#L15) and in the [TypeScriptParser.js](https://github.com/facebook/react-native/blob/main/packages/react-native-codegen/src/parsers/typescript/parser.js#L15). Update the signature of [assertGenericTypeAnnotationHasExactlyOneTypeParameter](https://github.com/facebook/react-native/blob/main/packages/react-native-codegen/src/parsers/parsers-commons.js#L67) function to take the Parser instead of the language and use the new function in place of the [ternary operator ?:](https://github.com/facebook/react-native/blob/main/packages/react-native-codegen/src/parsers/parsers-commons.js#L83).

There are 3 things I'm not sure about:
1. The issue suggests to create a new function. For this case I believe an attribute is simpler. Is there a reason to prefer a function ?
2. To update the tests I had to create a mocked parser. I created a new file `parserMock` (I took example on [AnimatedMock](https://github.com/facebook/react-native/blob/main/Libraries/Animated/AnimatedMock.js)). Does it seem ok ?
3. I'm not sure what to add in the documentation of `typeParameterInstantiation`

## Changelog

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[Internal] [Changed] - Replace ternary in assertGenericTypeAnnotationHasExactlyOneTypeParameter with typeParameterInstantiation attribute in parser

Pull Request resolved: facebook#35157

Test Plan: I tested using Jest and Flow commands.

Reviewed By: rshest

Differential Revision: D40889856

Pulled By: cipolleschi

fbshipit-source-id: 8d9a8e087852f98dcc3fc0ecf1d4a7153f482ce7

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

@@ -20,6 +20,9 @@ const {
 } = require('../parsers-commons.js');
 const {UnsupportedUnionTypeAnnotationParserError} = require('../errors');
 import type {UnionTypeAnnotationMemberType} from '../../CodegenSchema';
+import {MockedParser} from '../parserMock';
+
+const parser = new MockedParser();
 
 describe('wrapNullable', () => {
   describe('when nullable is true', () => {
@@ -101,7 +104,7 @@ describe('assertGenericTypeAnnotationHasExactlyOneTypeParameter', () => {
       assertGenericTypeAnnotationHasExactlyOneTypeParameter(
         moduleName,
         typeAnnotation,
-        'Flow',
+        parser,
       ),
     ).not.toThrow();
   });
@@ -117,14 +120,14 @@ describe('assertGenericTypeAnnotationHasExactlyOneTypeParameter', () => {
       assertGenericTypeAnnotationHasExactlyOneTypeParameter(
         moduleName,
         typeAnnotation,
-        'Flow',
+        parser,
       ),
     ).toThrowErrorMatchingInlineSnapshot(
       `"Module testModuleName: Generic 'typeAnnotationName' must have type parameters."`,
     );
   });
 
-  it('throws an error if typeAnnotation.typeParameters.type is not TypeParameterInstantiation when language is Flow', () => {
+  it('throws an error if typeAnnotation.typeParameters.type is not equal to parser.typeParameterInstantiation', () => {
     const flowTypeAnnotation = {
       typeParameters: {
         type: 'wrongType',
@@ -138,36 +141,14 @@ describe('assertGenericTypeAnnotationHasExactlyOneTypeParameter', () => {
       assertGenericTypeAnnotationHasExactlyOneTypeParameter(
         moduleName,
         flowTypeAnnotation,
-        'Flow',
+        parser,
       ),
     ).toThrowErrorMatchingInlineSnapshot(
       `"assertGenericTypeAnnotationHasExactlyOneTypeParameter: Type parameters must be an AST node of type 'TypeParameterInstantiation'"`,
     );
   });
 
-  it('throws an error if typeAnnotation.typeParameters.type is not TSTypeParameterInstantiation when language is TypeScript', () => {
-    const typeScriptTypeAnnotation = {
-      typeParameters: {
-        type: 'wrongType',
-        params: [1],
-      },
-      typeName: {
-        name: 'typeAnnotationName',
-      },
-    };
-    expect(() =>
-      assertGenericTypeAnnotationHasExactlyOneTypeParameter(
-        moduleName,
-        typeScriptTypeAnnotation,
-        'TypeScript',
-      ),
-    ).toThrowErrorMatchingInlineSnapshot(
-      `"assertGenericTypeAnnotationHasExactlyOneTypeParameter: Type parameters must be an AST node of type 'TSTypeParameterInstantiation'"`,
-    );
-  });
-
-  it("throws an IncorrectlyParameterizedGenericParserError if typeParameters don't have 1 exactly parameter for Flow", () => {
-    const language: ParserType = 'Flow';
+  it("throws an IncorrectlyParameterizedGenericParserError if typeParameters don't have 1 exactly parameter", () => {
     const typeAnnotationWithTwoParams = {
       typeParameters: {
         params: [1, 2],
@@ -181,7 +162,7 @@ describe('assertGenericTypeAnnotationHasExactlyOneTypeParameter', () => {
       assertGenericTypeAnnotationHasExactlyOneTypeParameter(
         moduleName,
         typeAnnotationWithTwoParams,
-        language,
+        parser,
       ),
     ).toThrowErrorMatchingInlineSnapshot(
       `"Module testModuleName: Generic 'typeAnnotationName' must have exactly one type parameter."`,
@@ -200,48 +181,7 @@ describe('assertGenericTypeAnnotationHasExactlyOneTypeParameter', () => {
       assertGenericTypeAnnotationHasExactlyOneTypeParameter(
         moduleName,
         typeAnnotationWithNoParams,
-        language,
-      ),
-    ).toThrowErrorMatchingInlineSnapshot(
-      `"Module testModuleName: Generic 'typeAnnotationName' must have exactly one type parameter."`,
-    );
-  });
-
-  it("throws an IncorrectlyParameterizedGenericParserError if typeParameters don't have 1 exactly parameter for TS", () => {
-    const language: ParserType = 'TypeScript';
-    const typeAnnotationWithTwoParams = {
-      typeParameters: {
-        params: [1, 2],
-        type: 'TSTypeParameterInstantiation',
-      },
-      typeName: {
-        name: 'typeAnnotationName',
-      },
-    };
-    expect(() =>
-      assertGenericTypeAnnotationHasExactlyOneTypeParameter(
-        moduleName,
-        typeAnnotationWithTwoParams,
-        language,
-      ),
-    ).toThrowErrorMatchingInlineSnapshot(
-      `"Module testModuleName: Generic 'typeAnnotationName' must have exactly one type parameter."`,
-    );
-
-    const typeAnnotationWithNoParams = {
-      typeParameters: {
-        params: [],
-        type: 'TSTypeParameterInstantiation',
-      },
-      typeName: {
-        name: 'typeAnnotationName',
-      },
-    };
-    expect(() =>
-      assertGenericTypeAnnotationHasExactlyOneTypeParameter(
-        moduleName,
-        typeAnnotationWithNoParams,
-        language,
+        parser,
       ),
     ).toThrowErrorMatchingInlineSnapshot(
       `"Module testModuleName: Generic 'typeAnnotationName' must have exactly one type parameter."`,

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

@@ -26,6 +26,9 @@ const {
   emitMixedTypeAnnotation,
   typeAliasResolution,
 } = require('../parsers-primitives.js');
+import {MockedParser} from '../parserMock';
+
+const parser = new MockedParser();
 
 describe('emitBoolean', () => {
   describe('when nullable is true', () => {
@@ -334,7 +337,7 @@ describe('typeAliasResolution', () => {
 
 describe('emitPromise', () => {
   const moduleName = 'testModuleName';
-  const language = 'Flow';
+
   describe("when typeAnnotation doesn't have exactly one typeParameter", () => {
     const typeAnnotation = {
       typeParameters: {
@@ -348,7 +351,7 @@ describe('emitPromise', () => {
     it('throws an IncorrectlyParameterizedGenericParserError error', () => {
       const nullable = false;
       expect(() =>
-        emitPromise(moduleName, typeAnnotation, language, nullable),
+        emitPromise(moduleName, typeAnnotation, parser, nullable),
       ).toThrow();
     });
   });
@@ -370,7 +373,7 @@ describe('emitPromise', () => {
         const result = emitPromise(
           moduleName,
           typeAnnotation,
-          language,
+          parser,
           nullable,
         );
         const expected = {
@@ -389,7 +392,7 @@ describe('emitPromise', () => {
         const result = emitPromise(
           moduleName,
           typeAnnotation,
-          language,
+          parser,
           nullable,
         );
         const expected = {

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

@@ -184,19 +184,14 @@ function translateTypeAnnotation(
           return emitRootTag(nullable);
         }
         case 'Promise': {
-          return emitPromise(
-            hasteModuleName,
-            typeAnnotation,
-            language,
-            nullable,
-          );
+          return emitPromise(hasteModuleName, typeAnnotation, parser, nullable);
         }
         case 'Array':
         case '$ReadOnlyArray': {
           assertGenericTypeAnnotationHasExactlyOneTypeParameter(
             hasteModuleName,
             typeAnnotation,
-            language,
+            parser,
           );
 
           return translateArrayTypeAnnotation(
@@ -213,7 +208,7 @@ function translateTypeAnnotation(
           assertGenericTypeAnnotationHasExactlyOneTypeParameter(
             hasteModuleName,
             typeAnnotation,
-            language,
+            parser,
           );
 
           const [paramType, isParamNullable] = unwrapNullable(

packages/react-native-codegen/src/parsers/flow/parser.js

@@ -14,6 +14,8 @@ import type {ParserType} from '../errors';
 import type {Parser} from '../parser';
 
 class FlowParser implements Parser {
+  typeParameterInstantiation: string = 'TypeParameterInstantiation';
+
   getMaybeEnumMemberType(maybeEnumDeclaration: $FlowFixMe): string {
     return maybeEnumDeclaration.body.type
       .replace('EnumNumberBody', 'NumberTypeAnnotation')

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

@@ -17,6 +17,11 @@ import type {ParserType} from './errors';
  * It exposes all the methods that contain language-specific logic.
  */
 export interface Parser {
+  /**
+   * This is the TypeParameterInstantiation value
+   */
+  typeParameterInstantiation: string;
+
   /**
    * Given a type declaration, it possibly returns the name of the Enum type.
    * @parameter maybeEnumDeclaration: an object possibly containing an Enum declaration.

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

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ */
+
+'use strict';
+
+import type {Parser} from './parser';
+import type {ParserType} from './errors';
+
+export class MockedParser implements Parser {
+  typeParameterInstantiation: string = 'TypeParameterInstantiation';
+
+  getMaybeEnumMemberType(maybeEnumDeclaration: $FlowFixMe): string {
+    return maybeEnumDeclaration.body.type
+      .replace('EnumNumberBody', 'NumberTypeAnnotation')
+      .replace('EnumStringBody', 'StringTypeAnnotation');
+  }
+
+  isEnumDeclaration(maybeEnumDeclaration: $FlowFixMe): boolean {
+    return maybeEnumDeclaration.type === 'EnumDeclaration';
+  }
+
+  language(): ParserType {
+    return 'Flow';
+  }
+
+  nameForGenericTypeAnnotation(typeAnnotation: $FlowFixMe): string {
+    return typeAnnotation.id.name;
+  }
+}

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

@@ -77,20 +77,17 @@ function assertGenericTypeAnnotationHasExactlyOneTypeParameter(
    * TODO(T108222691): Use flow-types for @babel/parser
    */
   typeAnnotation: $FlowFixMe,
-  language: ParserType,
+  parser: Parser,
 ) {
   if (typeAnnotation.typeParameters == null) {
     throw new MissingTypeParameterGenericParserError(
       moduleName,
       typeAnnotation,
-      language,
+      parser.language(),
     );
   }
 
-  const typeAnnotationType =
-    language === 'TypeScript'
-      ? 'TSTypeParameterInstantiation'
-      : 'TypeParameterInstantiation';
+  const typeAnnotationType = parser.typeParameterInstantiation;
 
   invariant(
     typeAnnotation.typeParameters.type === typeAnnotationType,
@@ -101,7 +98,7 @@ function assertGenericTypeAnnotationHasExactlyOneTypeParameter(
     throw new MoreThanOneTypeParameterGenericParserError(
       moduleName,
       typeAnnotation,
-      language,
+      parser.language(),
     );
   }
 }

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

@@ -32,6 +32,7 @@ import type {
   NamedShape,
 } from '../CodegenSchema';
 import type {ParserType} from './errors';
+import type {Parser} from './parser';
 import type {
   ParserErrorCapturer,
   TypeAliasResolutionStatus,
@@ -174,13 +175,13 @@ function typeAliasResolution(
 function emitPromise(
   hasteModuleName: string,
   typeAnnotation: $FlowFixMe,
-  language: ParserType,
+  parser: Parser,
   nullable: boolean,
 ): Nullable<NativeModulePromiseTypeAnnotation> {
   assertGenericTypeAnnotationHasExactlyOneTypeParameter(
     hasteModuleName,
     typeAnnotation,
-    language,
+    parser,
   );
 
   return wrapNullable(nullable, {

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

@@ -213,19 +213,14 @@ function translateTypeAnnotation(
           return emitRootTag(nullable);
         }
         case 'Promise': {
-          return emitPromise(
-            hasteModuleName,
-            typeAnnotation,
-            language,
-            nullable,
-          );
+          return emitPromise(hasteModuleName, typeAnnotation, parser, nullable);
         }
         case 'Array':
         case 'ReadonlyArray': {
           assertGenericTypeAnnotationHasExactlyOneTypeParameter(
             hasteModuleName,
             typeAnnotation,
-            language,
+            parser,
           );
 
           return translateArrayTypeAnnotation(

packages/react-native-codegen/src/parsers/typescript/parser.js

@@ -14,6 +14,8 @@ import type {ParserType} from '../errors';
 import type {Parser} from '../parser';
 
 class TypeScriptParser implements Parser {
+  typeParameterInstantiation: string = 'TSTypeParameterInstantiation';
+
   getMaybeEnumMemberType(maybeEnumDeclaration: $FlowFixMe): string {
     if (maybeEnumDeclaration.members[0].initializer) {
       return maybeEnumDeclaration.members[0].initializer.type