react-native-code-gen Add Union Type support for C++ TurboModules

Summary:
There are cases where we want to pass a union type into a TurboModule method which is handy to restrict certain arguments to a restricted set of values, e.g. restricting quality to ```'low'```, ```high``` or resolution to ```720```, ```1080```.

- We are not generating an ```union``` type in C++ but rather just cast type safe to the corresponding member type.

- We don't support mixed primitive union types at this time, e.g. ```export type ChooseSomething = 'One' | 'Two' | 3 | false;``` does not work.

- We can support mixed object union types such as ... ```export type ChooseObject = {} | {low: string};``` - which need special logic in the C++ TM to correctly parse the resulting jsi::Object

This is for C++ only, Java and ObjC are not supported atm.

Changelog:
[General][Added] - react-native-code-gen Add Union Type support for C++ TurboModules

Reviewed By: javache

Differential Revision: D38919688

fbshipit-source-id: 0fd37545b32b4f2059a8babda62dab4a85de37a9

packages/react-native-codegen/src/CodegenSchema.js

@@ -295,6 +295,16 @@ export type NativeModulePromiseTypeAnnotation = $ReadOnly<{
   type: 'PromiseTypeAnnotation',
 }>;
 
+export type UnionTypeAnnotationMemberType =
+  | 'NumberTypeAnnotation'
+  | 'ObjectTypeAnnotation'
+  | 'StringTypeAnnotation';
+
+export type NativeModuleUnionTypeAnnotation = $ReadOnly<{
+  type: 'UnionTypeAnnotation',
+  memberType: UnionTypeAnnotationMemberType,
+}>;
+
 export type NativeModuleMixedTypeAnnotation = $ReadOnly<{
   type: 'MixedTypeAnnotation',
 }>;
@@ -311,6 +321,7 @@ export type NativeModuleBaseTypeAnnotation =
   | NativeModuleTypeAliasTypeAnnotation
   | NativeModuleArrayTypeAnnotation<Nullable<NativeModuleBaseTypeAnnotation>>
   | NativeModuleObjectTypeAnnotation
+  | NativeModuleUnionTypeAnnotation
   | NativeModuleMixedTypeAnnotation;
 
 export type NativeModuleParamTypeAnnotation =

packages/react-native-codegen/src/generators/modules/GenerateModuleCpp.js

@@ -167,6 +167,19 @@ function serializeArg(
       return wrap(val => `${val}.asObject(rt).asFunction(rt)`);
     case 'GenericObjectTypeAnnotation':
       return wrap(val => `${val}.asObject(rt)`);
+    case 'UnionTypeAnnotation':
+      switch (typeAnnotation.memberType) {
+        case 'NumberTypeAnnotation':
+          return wrap(val => `${val}.asNumber()`);
+        case 'ObjectTypeAnnotation':
+          return wrap(val => `${val}.asObject(rt)`);
+        case 'StringTypeAnnotation':
+          return wrap(val => `${val}.asString(rt)`);
+        default:
+          throw new Error(
+            `Unsupported union member type for param  "${arg.name}, found: ${realTypeAnnotation.memberType}"`,
+          );
+      }
     case 'ObjectTypeAnnotation':
       return wrap(val => `${val}.asObject(rt)`);
     case 'MixedTypeAnnotation':

packages/react-native-codegen/src/generators/modules/GenerateModuleH.js

@@ -148,6 +148,17 @@ function translatePrimitiveJSTypeToCpp(
       return wrap('bool');
     case 'GenericObjectTypeAnnotation':
       return wrap('jsi::Object');
+    case 'UnionTypeAnnotation':
+      switch (typeAnnotation.memberType) {
+        case 'NumberTypeAnnotation':
+          return wrap('double');
+        case 'ObjectTypeAnnotation':
+          return wrap('jsi::Object');
+        case 'StringTypeAnnotation':
+          return wrap('jsi::String');
+        default:
+          throw new Error(createErrorMessage(realTypeAnnotation.type));
+      }
     case 'ObjectTypeAnnotation':
       return wrap('jsi::Object');
     case 'ArrayTypeAnnotation':

packages/react-native-codegen/src/generators/modules/GenerateModuleJavaSpec.js

@@ -156,7 +156,7 @@ function translateFunctionParamToJavaType(
       imports.add('com.facebook.react.bridge.Callback');
       return 'Callback';
     default:
-      (realTypeAnnotation.type: 'MixedTypeAnnotation');
+      (realTypeAnnotation.type: 'MixedTypeAnnotation' | 'UnionTypeAnnotation');
       throw new Error(createErrorMessage(realTypeAnnotation.type));
   }
 }
@@ -220,7 +220,7 @@ function translateFunctionReturnTypeToJavaType(
       imports.add('com.facebook.react.bridge.WritableArray');
       return wrapIntoNullableIfNeeded('WritableArray');
     default:
-      (realTypeAnnotation.type: 'MixedTypeAnnotation');
+      (realTypeAnnotation.type: 'MixedTypeAnnotation' | 'UnionTypeAnnotation');
       throw new Error(createErrorMessage(realTypeAnnotation.type));
   }
 }
@@ -272,7 +272,7 @@ function getFalsyReturnStatementFromReturnType(
     case 'ArrayTypeAnnotation':
       return 'return null;';
     default:
-      (realTypeAnnotation.type: 'MixedTypeAnnotation');
+      (realTypeAnnotation.type: 'MixedTypeAnnotation' | 'UnionTypeAnnotation');
       throw new Error(createErrorMessage(realTypeAnnotation.type));
   }
 }

packages/react-native-codegen/src/generators/modules/GenerateModuleJniCpp.js

@@ -171,7 +171,7 @@ function translateReturnTypeToKind(
     case 'ArrayTypeAnnotation':
       return 'ArrayKind';
     default:
-      (realTypeAnnotation.type: 'MixedTypeAnnotation');
+      (realTypeAnnotation.type: 'MixedTypeAnnotation' | 'UnionTypeAnnotation');
       throw new Error(
         `Unknown prop type for returning value, found: ${realTypeAnnotation.type}"`,
       );
@@ -226,7 +226,7 @@ function translateParamTypeToJniType(
     case 'FunctionTypeAnnotation':
       return 'Lcom/facebook/react/bridge/Callback;';
     default:
-      (realTypeAnnotation.type: 'MixedTypeAnnotation');
+      (realTypeAnnotation.type: 'MixedTypeAnnotation' | 'UnionTypeAnnotation');
       throw new Error(
         `Unknown prop type for method arg, found: ${realTypeAnnotation.type}"`,
       );
@@ -278,7 +278,7 @@ function translateReturnTypeToJniType(
     case 'ArrayTypeAnnotation':
       return 'Lcom/facebook/react/bridge/WritableArray;';
     default:
-      (realTypeAnnotation.type: 'MixedTypeAnnotation');
+      (realTypeAnnotation.type: 'MixedTypeAnnotation' | 'UnionTypeAnnotation');
       throw new Error(
         `Unknown prop type for method return type, found: ${realTypeAnnotation.type}"`,
       );

packages/react-native-codegen/src/generators/modules/GenerateModuleObjCpp/StructCollector.js

@@ -114,6 +114,8 @@ class StructCollector {
       }
       case 'MixedTypeAnnotation':
         throw new Error('Mixed types are unsupported in structs');
+      case 'UnionTypeAnnotation':
+        throw new Error('Union types are unsupported in structs');
       default: {
         return wrapNullable(nullable, typeAnnotation);
       }

packages/react-native-codegen/src/generators/modules/GenerateModuleObjCpp/serializeMethod.js

@@ -338,7 +338,7 @@ function getReturnObjCType(
     case 'GenericObjectTypeAnnotation':
       return wrapIntoNullableIfNeeded('NSDictionary *');
     default:
-      (typeAnnotation.type: 'MixedTypeAnnotation');
+      (typeAnnotation.type: 'MixedTypeAnnotation' | 'UnionTypeAnnotation');
       throw new Error(
         `Unsupported return type for ${methodName}. Found: ${typeAnnotation.type}`,
       );
@@ -378,7 +378,7 @@ function getReturnJSType(
     case 'GenericObjectTypeAnnotation':
       return 'ObjectKind';
     default:
-      (typeAnnotation.type: 'MixedTypeAnnotation');
+      (typeAnnotation.type: 'MixedTypeAnnotation' | 'UnionTypeAnnotation');
       throw new Error(
         `Unsupported return type for ${methodName}. Found: ${typeAnnotation.type}`,
       );

packages/react-native-codegen/src/generators/modules/__test_fixtures__/fixtures.js

@@ -1567,6 +1567,51 @@ const CXX_ONLY_NATIVE_MODULES: SchemaType = {
               ],
             },
           },
+          {
+            name: 'getUnion',
+            optional: false,
+            typeAnnotation: {
+              type: 'FunctionTypeAnnotation',
+              returnTypeAnnotation: {
+                type: 'UnionTypeAnnotation',
+                memberType: 'ObjectTypeAnnotation',
+              },
+              params: [
+                {
+                  name: 'chooseInt',
+                  optional: false,
+                  typeAnnotation: {
+                    type: 'UnionTypeAnnotation',
+                    memberType: 'NumberTypeAnnotation',
+                  },
+                },
+                {
+                  name: 'chooseFloat',
+                  optional: false,
+                  typeAnnotation: {
+                    type: 'UnionTypeAnnotation',
+                    memberType: 'NumberTypeAnnotation',
+                  },
+                },
+                {
+                  name: 'chooseObject',
+                  optional: false,
+                  typeAnnotation: {
+                    type: 'UnionTypeAnnotation',
+                    memberType: 'ObjectTypeAnnotation',
+                  },
+                },
+                {
+                  name: 'chooseString',
+                  optional: false,
+                  typeAnnotation: {
+                    type: 'UnionTypeAnnotation',
+                    memberType: 'StringTypeAnnotation',
+                  },
+                },
+              ],
+            },
+          },
         ],
       },
       moduleNames: ['SampleTurboModuleCxx'],

packages/react-native-codegen/src/generators/modules/__tests__/__snapshots__/GenerateModuleCpp-test.js.snap

@@ -115,11 +115,15 @@ static jsi::Value __hostFunction_NativeSampleTurboModuleCxxSpecJSI_getNullableNu
   auto result = static_cast<NativeSampleTurboModuleCxxSpecJSI *>(&turboModule)->getNullableNumberFromNullableAlias(rt, args[0].isNull() || args[0].isUndefined() ? std::nullopt : std::make_optional(args[0].asObject(rt)));
   return result ? jsi::Value(std::move(*result)) : jsi::Value::null();
 }
+static jsi::Value __hostFunction_NativeSampleTurboModuleCxxSpecJSI_getUnion(jsi::Runtime &rt, TurboModule &turboModule, const jsi::Value* args, size_t count) {
+  return static_cast<NativeSampleTurboModuleCxxSpecJSI *>(&turboModule)->getUnion(rt, args[0].asNumber(), args[1].asNumber(), args[2].asObject(rt), args[3].asString(rt));
+}
 
 NativeSampleTurboModuleCxxSpecJSI::NativeSampleTurboModuleCxxSpecJSI(std::shared_ptr<CallInvoker> jsInvoker)
   : TurboModule(\\"SampleTurboModuleCxx\\", jsInvoker) {
   methodMap_[\\"getMixed\\"] = MethodMetadata {1, __hostFunction_NativeSampleTurboModuleCxxSpecJSI_getMixed};
   methodMap_[\\"getNullableNumberFromNullableAlias\\"] = MethodMetadata {1, __hostFunction_NativeSampleTurboModuleCxxSpecJSI_getNullableNumberFromNullableAlias};
+  methodMap_[\\"getUnion\\"] = MethodMetadata {4, __hostFunction_NativeSampleTurboModuleCxxSpecJSI_getUnion};
 }
 
 

packages/react-native-codegen/src/generators/modules/__tests__/__snapshots__/GenerateModuleH-test.js.snap

@@ -209,6 +209,7 @@ protected:
 public:
   virtual jsi::Value getMixed(jsi::Runtime &rt, jsi::Value arg) = 0;
   virtual std::optional<double> getNullableNumberFromNullableAlias(jsi::Runtime &rt, std::optional<jsi::Object> a) = 0;
+  virtual jsi::Object getUnion(jsi::Runtime &rt, double chooseInt, double chooseFloat, jsi::Object chooseObject, jsi::String chooseString) = 0;
 
 };
 
@@ -246,6 +247,14 @@ private:
       return bridging::callFromJs<std::optional<double>>(
           rt, &T::getNullableNumberFromNullableAlias, jsInvoker_, instance_, std::move(a));
     }
+    jsi::Object getUnion(jsi::Runtime &rt, double chooseInt, double chooseFloat, jsi::Object chooseObject, jsi::String chooseString) override {
+      static_assert(
+          bridging::getParameterCount(&T::getUnion) == 5,
+          \\"Expected getUnion(...) to have 5 parameters\\");
+
+      return bridging::callFromJs<jsi::Object>(
+          rt, &T::getUnion, jsInvoker_, instance_, std::move(chooseInt), std::move(chooseFloat), std::move(chooseObject), std::move(chooseString));
+    }
 
   private:
     T *instance_;

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

@@ -593,9 +593,15 @@ const CXX_ONLY_NATIVE_MODULE = `
 import type {TurboModule} from '../RCTExport';
 import * as TurboModuleRegistry from '../TurboModuleRegistry';
 
+export type ChooseInt = 1 | 2 | 3;
+export type ChooseFloat = 1.44 | 2.88 | 5.76;
+export type ChooseObject = {} | {low: string};
+export type ChooseString = 'One' | 'Two' | 'Three';
+
 export interface Spec extends TurboModule {
   +getCallback: () => () => void;
   +getMixed: (arg: mixed) => mixed;
+  +getUnion: (chooseInt: ChooseInt, chooseFloat: ChooseFloat, chooseObject: ChooseObject, chooseString: ChooseString) => ChooseObject;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>('SampleTurboModuleCxx');

packages/react-native-codegen/src/parsers/flow/modules/__tests__/__snapshots__/module-parser-snapshot-test.js.snap

@@ -77,6 +77,51 @@ exports[`RN Codegen Flow Parser can generate fixture CXX_ONLY_NATIVE_MODULE 1`]
                 }
               ]
             }
+          },
+          {
+            'name': 'getUnion',
+            'optional': false,
+            'typeAnnotation': {
+              'type': 'FunctionTypeAnnotation',
+              'returnTypeAnnotation': {
+                'type': 'UnionTypeAnnotation',
+                'memberType': 'ObjectTypeAnnotation'
+              },
+              'params': [
+                {
+                  'name': 'chooseInt',
+                  'optional': false,
+                  'typeAnnotation': {
+                    'type': 'UnionTypeAnnotation',
+                    'memberType': 'NumberTypeAnnotation'
+                  }
+                },
+                {
+                  'name': 'chooseFloat',
+                  'optional': false,
+                  'typeAnnotation': {
+                    'type': 'UnionTypeAnnotation',
+                    'memberType': 'NumberTypeAnnotation'
+                  }
+                },
+                {
+                  'name': 'chooseObject',
+                  'optional': false,
+                  'typeAnnotation': {
+                    'type': 'UnionTypeAnnotation',
+                    'memberType': 'ObjectTypeAnnotation'
+                  }
+                },
+                {
+                  'name': 'chooseString',
+                  'optional': false,
+                  'typeAnnotation': {
+                    'type': 'UnionTypeAnnotation',
+                    'memberType': 'StringTypeAnnotation'
+                  }
+                }
+              ]
+            }
           }
         ]
       },

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

@@ -227,6 +227,30 @@ class UnsupportedFunctionReturnTypeAnnotationParserError extends ParserError {
   }
 }
 
+/**
+ * Union parsing errors
+ */
+
+class UnsupportedUnionTypeAnnotationParserError extends ParserError {
+  constructor(
+    hasteModuleName: string,
+    arrayElementTypeAST: $FlowFixMe,
+    types: string[],
+  ) {
+    super(
+      hasteModuleName,
+      arrayElementTypeAST,
+      `Union members must be of the same type, but multiple types were found ${types.join(
+        ', ',
+      )}'.`,
+    );
+  }
+}
+
+/**
+ * Module parsing errors
+ */
+
 class UnusedModuleFlowInterfaceParserError extends ParserError {
   constructor(hasteModuleName: string, flowInterface: $FlowFixMe) {
     super(
@@ -323,6 +347,7 @@ module.exports = {
   UnsupportedFlowTypeAnnotationParserError,
   UnsupportedFunctionParamTypeAnnotationParserError,
   UnsupportedFunctionReturnTypeAnnotationParserError,
+  UnsupportedUnionTypeAnnotationParserError,
   UnsupportedModulePropertyParserError,
   UnsupportedObjectPropertyTypeAnnotationParserError,
   UnsupportedObjectPropertyValueTypeAnnotationParserError,

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

@@ -44,6 +44,7 @@ const {
   UnsupportedFlowTypeAnnotationParserError,
   UnsupportedFunctionParamTypeAnnotationParserError,
   UnsupportedFunctionReturnTypeAnnotationParserError,
+  UnsupportedUnionTypeAnnotationParserError,
   UnsupportedModulePropertyParserError,
   UnsupportedObjectPropertyTypeAnnotationParserError,
   UnsupportedObjectPropertyValueTypeAnnotationParserError,
@@ -367,6 +368,33 @@ function translateTypeAnnotation(
         ),
       );
     }
+    case 'UnionTypeAnnotation': {
+      if (cxxOnly) {
+        // Remap literal names
+        const unionTypes = typeAnnotation.types
+          .map(
+            item =>
+              item.type
+                .replace('NumberLiteralTypeAnnotation', 'NumberTypeAnnotation')
+                .replace('StringLiteralTypeAnnotation', 'StringTypeAnnotation'),
+            // ObjectAnnotation is already 'correct'
+          )
+          .filter((value, index, self) => self.indexOf(value) === index);
+        // Only support unionTypes of the same kind
+        if (unionTypes.length > 1) {
+          throw new UnsupportedUnionTypeAnnotationParserError(
+            hasteModuleName,
+            typeAnnotation,
+            unionTypes,
+          );
+        }
+        return wrapNullable(nullable, {
+          type: 'UnionTypeAnnotation',
+          memberType: unionTypes[0],
+        });
+      }
+      // Fallthrough
+    }
     case 'MixedTypeAnnotation': {
       if (cxxOnly) {
         return wrapNullable(nullable, {

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

@@ -608,9 +608,15 @@ const CXX_ONLY_NATIVE_MODULE = `
 import type {TurboModule} from 'react-native/Libraries/TurboModule/RCTExport';
 import * as TurboModuleRegistry from 'react-native/Libraries/TurboModule/TurboModuleRegistry';
 
+export type ChooseInt = 1 | 2 | 3;
+export type ChooseFloat = 1.44 | 2.88 | 5.76;
+export type ChooseObject = {} | {low: string};
+export type ChooseString = 'One' | 'Two' | 'Three';
+
 export interface Spec extends TurboModule {
   readonly getCallback: () => () => void;
   readonly getMixed: (arg: unknown) => unknown;
+  readonly getUnion: (chooseInt: ChooseInt, chooseFloat: ChooseFloat, chooseObject: ChooseObject, chooseString: ChooseString) => ChooseObject;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(