Add support for Arrays in generator (facebook#37145)

Summary:
Pull Request resolved: facebook#37145

This diff adds the generation of Array types in events.

It supports the generation of Array of:
- Boolean
- Int32
- Float
- Double
- String
- Objects
- Array

**Note:** This is a first iteration. We could improve the generation further by leveraging the `Bridging` module within React Native.
I'll take a stab at it in a next diff.

## Changelog:
[General][Added] - Generate events with arrays

Differential Revision: D45321685

fbshipit-source-id: 2544ad151738fd4ba185b20fe17daa09b8d98d48

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

@@ -49,6 +49,42 @@ function getCppTypeForAnnotation(
   }
 }
 
+function getCppArrayTypeForAnnotation(
+  typeElement: EventTypeAnnotation,
+  structParts?: string[],
+): string {
+  switch (typeElement.type) {
+    case 'BooleanTypeAnnotation':
+    case 'StringTypeAnnotation':
+    case 'DoubleTypeAnnotation':
+    case 'FloatTypeAnnotation':
+    case 'Int32TypeAnnotation':
+    case 'MixedTypeAnnotation':
+      return `std::vector<${getCppTypeForAnnotation(typeElement.type)}>`;
+    case 'StringEnumTypeAnnotation':
+    case 'ObjectTypeAnnotation':
+      if (!structParts) {
+        throw new Error(
+          `Trying to generate the event emitter for an Array of ${typeElement.type} without informations to generate the generic type`,
+        );
+      }
+      return `std::vector<${generateEventStructName(structParts)}>`;
+    case 'ArrayTypeAnnotation':
+      return `std::vector<${getCppArrayTypeForAnnotation(
+        typeElement.elementType,
+        structParts,
+      )}>`;
+    default:
+      throw new Error(
+        `Can't determine array type with typeElement: ${JSON.stringify(
+          typeElement,
+          null,
+          2,
+        )}`,
+      );
+  }
+}
+
 function getImports(
   properties:
     | $ReadOnlyArray<NamedShape<PropTypeAnnotation>>
@@ -222,6 +258,7 @@ function convertDefaultTypeToString(
 
 module.exports = {
   convertDefaultTypeToString,
+  getCppArrayTypeForAnnotation,
   getCppTypeForAnnotation,
   getEnumMaskName,
   getImports,

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

@@ -102,9 +102,12 @@ function generateSetter(
   variableName: string,
   propertyName: string,
   propertyParts: $ReadOnlyArray<string>,
+  usingEvent: boolean,
   valueMapper: string => string = value => value,
 ) {
-  const eventChain = `$event.${[...propertyParts, propertyName].join('.')}`;
+  const eventChain = usingEvent
+    ? `$event.${[...propertyParts, propertyName].join('.')}`
+    : [propertyParts, propertyName].join('.');
   return `${variableName}.setProperty(runtime, "${propertyName}", ${valueMapper(
     eventChain,
   )});`;
@@ -116,6 +119,7 @@ function generateObjectSetter(
   propertyParts: $ReadOnlyArray<string>,
   typeAnnotation: ObjectTypeAnnotation<EventTypeAnnotation>,
   extraIncludes: Set<string>,
+  usingEvent: boolean,
 ) {
   return `
 {
@@ -126,6 +130,7 @@ function generateObjectSetter(
       typeAnnotation.properties,
       propertyParts.concat([propertyName]),
       extraIncludes,
+      usingEvent,
     ),
     2,
   )}
@@ -134,11 +139,165 @@ function generateObjectSetter(
 `.trim();
 }
 
+function setValueAtIndex(
+  propertyName: string,
+  indexVariable: string,
+  loopLocalVariable: string,
+  mappingFunction: string => string = value => value,
+) {
+  return `${propertyName}.setValueAtIndex(runtime, ${indexVariable}++, ${mappingFunction(
+    loopLocalVariable,
+  )});`;
+}
+
+function generateArraySetter(
+  variableName: string,
+  propertyName: string,
+  propertyParts: $ReadOnlyArray<string>,
+  elementType: EventTypeAnnotation,
+  extraIncludes: Set<string>,
+  usingEvent: boolean,
+): string {
+  const eventChain = usingEvent
+    ? `$event.${[...propertyParts, propertyName].join('.')}`
+    : [propertyParts, propertyName].join('.');
+  const indexVar = `${propertyName}Index`;
+  const innerLoopVar = `${propertyName}Value`;
+  return `
+    auto ${propertyName} = jsi::Array(runtime, ${eventChain}.size());
+    size_t ${indexVar} = 0;
+    for (auto ${innerLoopVar} : ${eventChain}) {
+      ${handleArrayElementType(
+        elementType,
+        propertyName,
+        indexVar,
+        innerLoopVar,
+        propertyParts,
+        extraIncludes,
+        usingEvent,
+      )}
+    }
+    ${variableName}.setProperty(runtime, "${propertyName}", ${propertyName});
+  `;
+}
+
+function handleArrayElementType(
+  elementType: EventTypeAnnotation,
+  propertyName: string,
+  indexVariable: string,
+  loopLocalVariable: string,
+  propertyParts: $ReadOnlyArray<string>,
+  extraIncludes: Set<string>,
+  usingEvent: boolean,
+): string {
+  switch (elementType.type) {
+    case 'BooleanTypeAnnotation':
+      return setValueAtIndex(
+        propertyName,
+        indexVariable,
+        loopLocalVariable,
+        val => `(bool)${val}`,
+      );
+    case 'StringTypeAnnotation':
+    case 'Int32TypeAnnotation':
+    case 'DoubleTypeAnnotation':
+    case 'FloatTypeAnnotation':
+      return setValueAtIndex(propertyName, indexVariable, loopLocalVariable);
+    case 'MixedTypeAnnotation':
+      return setValueAtIndex(
+        propertyName,
+        indexVariable,
+        loopLocalVariable,
+        val => `jsi::valueFromDynamic(runtime, ${val})`,
+      );
+    case 'StringEnumTypeAnnotation':
+      return setValueAtIndex(
+        propertyName,
+        indexVariable,
+        loopLocalVariable,
+        val => `toString(${val})`,
+      );
+    case 'ObjectTypeAnnotation':
+      return convertObjectTypeArray(
+        propertyName,
+        indexVariable,
+        loopLocalVariable,
+        propertyParts,
+        elementType,
+        extraIncludes,
+      );
+    case 'ArrayTypeAnnotation':
+      return convertArrayTypeArray(
+        propertyName,
+        indexVariable,
+        loopLocalVariable,
+        propertyParts,
+        elementType,
+        extraIncludes,
+        usingEvent,
+      );
+    default:
+      throw new Error(
+        `Received invalid elementType for array ${elementType.type}`,
+      );
+  }
+}
+
+function convertObjectTypeArray(
+  propertyName: string,
+  indexVariable: string,
+  loopLocalVariable: string,
+  propertyParts: $ReadOnlyArray<string>,
+  objectTypeAnnotation: ObjectTypeAnnotation<EventTypeAnnotation>,
+  extraIncludes: Set<string>,
+): string {
+  return `auto ${propertyName}Object = jsi::Object(runtime);
+      ${generateSetters(
+        `${propertyName}Object`,
+        objectTypeAnnotation.properties,
+        [].concat([loopLocalVariable]),
+        extraIncludes,
+        false,
+      )}
+      ${setValueAtIndex(propertyName, indexVariable, `${propertyName}Object`)}`;
+}
+
+function convertArrayTypeArray(
+  propertyName: string,
+  indexVariable: string,
+  loopLocalVariable: string,
+  propertyParts: $ReadOnlyArray<string>,
+  eventTypeAnnotation: EventTypeAnnotation,
+  extraIncludes: Set<string>,
+  usingEvent: boolean,
+): string {
+  if (eventTypeAnnotation.type !== 'ArrayTypeAnnotation') {
+    throw new Error(
+      `Inconsistent eventTypeAnnotation received. Expected type = 'ArrayTypeAnnotation'; received = ${eventTypeAnnotation.type}`,
+    );
+  }
+  return `auto ${propertyName}Array = jsi::Array(runtime, ${loopLocalVariable}.size());
+      size_t ${indexVariable}Internal = 0;
+      for (auto ${loopLocalVariable}Internal : ${loopLocalVariable}) {
+        ${handleArrayElementType(
+          eventTypeAnnotation.elementType,
+          `${propertyName}Array`,
+          `${indexVariable}Internal`,
+          `${loopLocalVariable}Internal`,
+          propertyParts,
+          extraIncludes,
+          usingEvent,
+        )}
+      }
+      ${setValueAtIndex(propertyName, indexVariable, `${propertyName}Array`)}`;
+}
+
 function generateSetters(
   parentPropertyName: string,
   properties: $ReadOnlyArray<NamedShape<EventTypeAnnotation>>,
   propertyParts: $ReadOnlyArray<string>,
   extraIncludes: Set<string>,
+  usingEvent: boolean = true,
 ): string {
   const propSetters = properties
     .map(eventProperty => {
@@ -153,20 +312,23 @@ function generateSetters(
             parentPropertyName,
             eventProperty.name,
             propertyParts,
+            usingEvent,
           );
         case 'MixedTypeAnnotation':
           extraIncludes.add('#include <jsi/JSIDynamic.h>');
           return generateSetter(
             parentPropertyName,
             eventProperty.name,
             propertyParts,
+            usingEvent,
             prop => `jsi::valueFromDynamic(runtime, ${prop})`,
           );
         case 'StringEnumTypeAnnotation':
           return generateSetter(
             parentPropertyName,
             eventProperty.name,
             propertyParts,
+            usingEvent,
             prop => `toString(${prop})`,
           );
         case 'ObjectTypeAnnotation':
@@ -176,10 +338,17 @@ function generateSetters(
             propertyParts,
             typeAnnotation,
             extraIncludes,
+            usingEvent,
           );
         case 'ArrayTypeAnnotation':
-          // TODO: implement this in the next diff
-          break;
+          return generateArraySetter(
+            parentPropertyName,
+            eventProperty.name,
+            propertyParts,
+            typeAnnotation.elementType,
+            extraIncludes,
+            usingEvent,
+          );
         default:
           (typeAnnotation.type: empty);
           throw new Error(

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

@@ -14,6 +14,7 @@ const nullthrows = require('nullthrows');
 
 const {
   getImports,
+  getCppArrayTypeForAnnotation,
   getCppTypeForAnnotation,
   generateEventStructName,
 } = require('./CppHelpers');
@@ -134,8 +135,16 @@ function getNativeTypeFromAnnotation(
     case 'ObjectTypeAnnotation':
       return generateEventStructName([...nameParts, eventProperty.name]);
     case 'ArrayTypeAnnotation':
-      // TODO: implement this in the next diff
-      return '';
+      const eventTypeAnnotation = eventProperty.typeAnnotation;
+      if (eventTypeAnnotation.type !== 'ArrayTypeAnnotation') {
+        throw new Error(
+          "Inconsistent Codegen state: type was ArrayTypeAnnotation at the beginning of the body and now it isn't",
+        );
+      }
+      return getCppArrayTypeForAnnotation(eventTypeAnnotation.elementType, [
+        ...nameParts,
+        eventProperty.name,
+      ]);
     default:
       (type: empty);
       throw new Error(`Received invalid event property type ${type}`);
@@ -168,6 +177,33 @@ function generateEnum(
   );
 }
 
+function handleGenerateStructForArray(
+  structs: StructsMap,
+  name: string,
+  componentName: string,
+  elementType: EventTypeAnnotation,
+  nameParts: $ReadOnlyArray<string>,
+): void {
+  if (elementType.type === 'ObjectTypeAnnotation') {
+    generateStruct(
+      structs,
+      componentName,
+      nameParts.concat([name]),
+      nullthrows(elementType.properties),
+    );
+  } else if (elementType.type === 'StringEnumTypeAnnotation') {
+    generateEnum(structs, elementType.options, nameParts.concat([name]));
+  } else if (elementType.type === 'ArrayTypeAnnotation') {
+    handleGenerateStructForArray(
+      structs,
+      name,
+      componentName,
+      elementType.elementType,
+      nameParts,
+    );
+  }
+}
+
 function generateStruct(
   structs: StructsMap,
   componentName: string,
@@ -197,6 +233,15 @@ function generateStruct(
       case 'FloatTypeAnnotation':
       case 'MixedTypeAnnotation':
         return;
+      case 'ArrayTypeAnnotation':
+        handleGenerateStructForArray(
+          structs,
+          name,
+          componentName,
+          typeAnnotation.elementType,
+          nameParts,
+        );
+        return;
       case 'ObjectTypeAnnotation':
         generateStruct(
           structs,
@@ -208,9 +253,6 @@ function generateStruct(
       case 'StringEnumTypeAnnotation':
         generateEnum(structs, typeAnnotation.options, nameParts.concat([name]));
         return;
-      case 'ArrayTypeAnnotation':
-        //TODO: implement this in the next diff
-        break;
       default:
         (typeAnnotation.type: empty);
         throw new Error(
@@ -277,7 +319,7 @@ module.exports = {
       .map(moduleName => {
         const module = schema.modules[moduleName];
         if (module.type !== 'Component') {
-          return;
+          return null;
         }
 
         const {components} = module;