Implement optional object props generation (#54726)

Summary:
Pull Request resolved: #54726

Add support for generating native optional object properties for custom types. This also updates the serialization of the custom type instances to only include properties that are defined on the object.

Changelog: [Internal]

Reviewed By: sammy-SC

Differential Revision: D87843979

fbshipit-source-id: c99179d7b48df62e836ab66dfad99f0723516af7

Author: Nick Lefever

packages/react-native-codegen/src/generators/components/GeneratePropsH.js

@@ -590,7 +590,12 @@ function generateStructsForComponent(
   componentName: string,
   component: ComponentShape,
 ): string {
-  const structs = generateStructs(componentName, component.props, []);
+  const structs = generateStructs(
+    componentName,
+    component.props,
+    [],
+    component.generateOptionalObjectProperties,
+  );
   const structArray = Array.from(structs.values());
   if (structArray.length < 1) {
     return '';
@@ -602,6 +607,7 @@ function generateStructs(
   componentName: string,
   properties: $ReadOnlyArray<NamedShape<PropTypeAnnotation>>,
   nameParts: Array<string>,
+  generateOptionalObjectProperties?: boolean = false,
 ): StructsMap {
   const structs: StructsMap = new Map();
   properties.forEach(prop => {
@@ -614,6 +620,7 @@ function generateStructs(
         componentName,
         elementProperties,
         nameParts.concat([prop.name]),
+        generateOptionalObjectProperties,
       );
       nestedStructs.forEach(function (value, key) {
         structs.set(key, value);
@@ -624,6 +631,7 @@ function generateStructs(
         componentName,
         nameParts.concat([prop.name]),
         typeAnnotation.properties,
+        generateOptionalObjectProperties,
       );
     }
 
@@ -638,6 +646,7 @@ function generateStructs(
         componentName,
         elementProperties,
         nameParts.concat([prop.name]),
+        generateOptionalObjectProperties,
       );
       nestedStructs.forEach(function (value, key) {
         structs.set(key, value);
@@ -649,6 +658,7 @@ function generateStructs(
         componentName,
         nameParts.concat([prop.name]),
         elementProperties,
+        generateOptionalObjectProperties,
       );
 
       // Generate the conversion function for std:vector<Object>.
@@ -679,6 +689,7 @@ function generateStructs(
         componentName,
         elementProperties,
         nameParts.concat([prop.name]),
+        generateOptionalObjectProperties,
       );
       nestedStructs.forEach(function (value, key) {
         structs.set(key, value);
@@ -690,6 +701,7 @@ function generateStructs(
         componentName,
         nameParts.concat([prop.name]),
         elementProperties,
+        generateOptionalObjectProperties,
       );
 
       // Generate the conversion function for std:vector<Object>.
@@ -716,13 +728,15 @@ function generateStruct(
   componentName: string,
   nameParts: $ReadOnlyArray<string>,
   properties: $ReadOnlyArray<NamedShape<PropTypeAnnotation>>,
+  generateOptionalObjectProperties?: boolean = false,
 ): void {
   const structNameParts = nameParts;
   const structName = generateStructName(componentName, structNameParts);
   const fields = generatePropsString(
     componentName,
     properties,
     structNameParts,
+    generateOptionalObjectProperties,
   );
 
   properties.forEach((property: NamedShape<PropTypeAnnotation>) => {
@@ -753,7 +767,13 @@ function generateStruct(
             `Properties are expected for ObjectTypeAnnotation (see ${name} in ${componentName})`,
           );
         }
-        generateStruct(structs, componentName, nameParts.concat([name]), props);
+        generateStruct(
+          structs,
+          componentName,
+          nameParts.concat([name]),
+          props,
+          generateOptionalObjectProperties,
+        );
         return;
       case 'MixedTypeAnnotation':
         return;
@@ -785,9 +805,29 @@ function generateStruct(
         case 'DoubleTypeAnnotation':
         case 'FloatTypeAnnotation':
         case 'MixedTypeAnnotation':
-          return `result["${name}"] = ${name};`;
+          if (
+            property.optional &&
+            property.typeAnnotation.default == null &&
+            generateOptionalObjectProperties
+          ) {
+            return `if (${name}.has_value()) {
+      result["${name}"] = ${name}.value();
+    }`;
+          } else {
+            return `result["${name}"] = ${name};`;
+          }
         default:
-          return `result["${name}"] = ::facebook::react::toDynamic(${name});`;
+          if (
+            property.optional &&
+            property.typeAnnotation.default == null &&
+            generateOptionalObjectProperties
+          ) {
+            return `if (${name}.has_value()) {
+      result["${name}"] = ::facebook::react::toDynamic(${name}.value());
+    }`;
+          } else {
+            return `result["${name}"] = ::facebook::react::toDynamic(${name});`;
+          }
       }
     })
     .join('\n    ');