Do not use $ in identifiers for event emitters. (#49792)

Summary:
Pull Request resolved: #49792

This removes the `$` from the `event` and `payload` identifier inside codegen.
This is causing the `-Wdollar-in-identifier-extension` warning to fire.

As I'm looking into enabling `-Wall -Werror` for React Common, this should be addressed as well.

Changelog:
[Internal] [Changed] -

Reviewed By: cipolleschi

Differential Revision: D70500543

fbshipit-source-id: c593680961b1b98561c3985f92ade5d6ba448ac9

Author: cortinico

packages/react-native-codegen/e2e/__tests__/components/__snapshots__/GenerateEventEmitterCpp-test.js.snap

@@ -149,22 +149,22 @@ Object {
 
 namespace facebook::react {
 
-void EventNestedObjectPropsNativeComponentViewEventEmitter::onChange(OnChange $event) const {
-  dispatchEvent(\\"change\\", [$event=std::move($event)](jsi::Runtime &runtime) {
-    auto $payload = jsi::Object(runtime);
+void EventNestedObjectPropsNativeComponentViewEventEmitter::onChange(OnChange event) const {
+  dispatchEvent(\\"change\\", [event=std::move(event)](jsi::Runtime &runtime) {
+    auto payload = jsi::Object(runtime);
     {
   auto location = jsi::Object(runtime);
   {
     auto source = jsi::Object(runtime);
-    source.setProperty(runtime, \\"url\\", $event.location.source.url);
+    source.setProperty(runtime, \\"url\\", event.location.source.url);
     location.setProperty(runtime, \\"source\\", source);
   }
-  location.setProperty(runtime, \\"x\\", $event.location.x);
-  location.setProperty(runtime, \\"y\\", $event.location.y);
+  location.setProperty(runtime, \\"x\\", event.location.x);
+  location.setProperty(runtime, \\"y\\", event.location.y);
 
-      auto arrayOfObjects = jsi::Array(runtime, $event.location.arrayOfObjects.size());
+      auto arrayOfObjects = jsi::Array(runtime, event.location.arrayOfObjects.size());
       size_t arrayOfObjectsIndex = 0;
-      for (auto arrayOfObjectsValue : $event.location.arrayOfObjects) {
+      for (auto arrayOfObjectsValue : event.location.arrayOfObjects) {
         auto arrayOfObjectsObject = jsi::Object(runtime);
         {
     auto value = jsi::Object(runtime);
@@ -175,9 +175,9 @@ void EventNestedObjectPropsNativeComponentViewEventEmitter::onChange(OnChange $e
       }
       location.setProperty(runtime, \\"arrayOfObjects\\", arrayOfObjects);
     
-  $payload.setProperty(runtime, \\"location\\", location);
+  payload.setProperty(runtime, \\"location\\", location);
 }
-    return $payload;
+    return payload;
   });
 }
 
@@ -203,59 +203,59 @@ Object {
 
 namespace facebook::react {
 
-void EventPropsNativeComponentViewEventEmitter::onChange(OnChange $event) const {
-  dispatchEvent(\\"paperDirectName\\", [$event=std::move($event)](jsi::Runtime &runtime) {
-    auto $payload = jsi::Object(runtime);
-    $payload.setProperty(runtime, \\"value\\", $event.value);
-$payload.setProperty(runtime, \\"source\\", $event.source);
-$payload.setProperty(runtime, \\"progress\\", $event.progress);
-$payload.setProperty(runtime, \\"scale\\", $event.scale);
-    return $payload;
+void EventPropsNativeComponentViewEventEmitter::onChange(OnChange event) const {
+  dispatchEvent(\\"paperDirectName\\", [event=std::move(event)](jsi::Runtime &runtime) {
+    auto payload = jsi::Object(runtime);
+    payload.setProperty(runtime, \\"value\\", event.value);
+payload.setProperty(runtime, \\"source\\", event.source);
+payload.setProperty(runtime, \\"progress\\", event.progress);
+payload.setProperty(runtime, \\"scale\\", event.scale);
+    return payload;
   });
 }
 
 
-void EventPropsNativeComponentViewEventEmitter::onEventDirect(OnEventDirect $event) const {
-  dispatchEvent(\\"eventDirect\\", [$event=std::move($event)](jsi::Runtime &runtime) {
-    auto $payload = jsi::Object(runtime);
-    $payload.setProperty(runtime, \\"value\\", $event.value);
-    return $payload;
+void EventPropsNativeComponentViewEventEmitter::onEventDirect(OnEventDirect event) const {
+  dispatchEvent(\\"eventDirect\\", [event=std::move(event)](jsi::Runtime &runtime) {
+    auto payload = jsi::Object(runtime);
+    payload.setProperty(runtime, \\"value\\", event.value);
+    return payload;
   });
 }
 
 
-void EventPropsNativeComponentViewEventEmitter::onEventDirectWithPaperName(OnEventDirectWithPaperName $event) const {
-  dispatchEvent(\\"paperDirectName\\", [$event=std::move($event)](jsi::Runtime &runtime) {
-    auto $payload = jsi::Object(runtime);
-    $payload.setProperty(runtime, \\"value\\", $event.value);
-    return $payload;
+void EventPropsNativeComponentViewEventEmitter::onEventDirectWithPaperName(OnEventDirectWithPaperName event) const {
+  dispatchEvent(\\"paperDirectName\\", [event=std::move(event)](jsi::Runtime &runtime) {
+    auto payload = jsi::Object(runtime);
+    payload.setProperty(runtime, \\"value\\", event.value);
+    return payload;
   });
 }
 
 
-void EventPropsNativeComponentViewEventEmitter::onOrientationChange(OnOrientationChange $event) const {
-  dispatchEvent(\\"paperBubblingName\\", [$event=std::move($event)](jsi::Runtime &runtime) {
-    auto $payload = jsi::Object(runtime);
-    $payload.setProperty(runtime, \\"orientation\\", toString($event.orientation));
-    return $payload;
+void EventPropsNativeComponentViewEventEmitter::onOrientationChange(OnOrientationChange event) const {
+  dispatchEvent(\\"paperBubblingName\\", [event=std::move(event)](jsi::Runtime &runtime) {
+    auto payload = jsi::Object(runtime);
+    payload.setProperty(runtime, \\"orientation\\", toString(event.orientation));
+    return payload;
   });
 }
 
 
-void EventPropsNativeComponentViewEventEmitter::onEnd(OnEnd $event) const {
+void EventPropsNativeComponentViewEventEmitter::onEnd(OnEnd event) const {
   dispatchEvent(\\"end\\", [](jsi::Runtime &runtime) {
-    auto $payload = jsi::Object(runtime);
+    auto payload = jsi::Object(runtime);
     
-    return $payload;
+    return payload;
   });
 }
 
 
-void EventPropsNativeComponentViewEventEmitter::onEventBubblingWithPaperName(OnEventBubblingWithPaperName $event) const {
+void EventPropsNativeComponentViewEventEmitter::onEventBubblingWithPaperName(OnEventBubblingWithPaperName event) const {
   dispatchEvent(\\"paperBubblingName\\", [](jsi::Runtime &runtime) {
-    auto $payload = jsi::Object(runtime);
+    auto payload = jsi::Object(runtime);
     
-    return $payload;
+    return payload;
   });
 }
 
@@ -347,11 +347,11 @@ Object {
 
 namespace facebook::react {
 
-void InterfaceOnlyNativeComponentViewEventEmitter::onChange(OnChange $event) const {
-  dispatchEvent(\\"change\\", [$event=std::move($event)](jsi::Runtime &runtime) {
-    auto $payload = jsi::Object(runtime);
-    $payload.setProperty(runtime, \\"value\\", $event.value);
-    return $payload;
+void InterfaceOnlyNativeComponentViewEventEmitter::onChange(OnChange event) const {
+  dispatchEvent(\\"change\\", [event=std::move(event)](jsi::Runtime &runtime) {
+    auto payload = jsi::Object(runtime);
+    payload.setProperty(runtime, \\"value\\", event.value);
+    return payload;
   });
 }
 

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

@@ -68,11 +68,11 @@ const ComponentTemplate = ({
   dispatchEventName: string,
   implementation: string,
 }) => {
-  const capture = implementation.includes('$event')
-    ? '$event=std::move($event)'
+  const capture = implementation.includes('event')
+    ? 'event=std::move(event)'
     : '';
   return `
-void ${className}EventEmitter::${eventName}(${structName} $event) const {
+void ${className}EventEmitter::${eventName}(${structName} event) const {
   dispatchEvent("${dispatchEventName}", [${capture}](jsi::Runtime &runtime) {
     ${implementation}
   });
@@ -103,7 +103,7 @@ function generateSetter(
   valueMapper: string => string = value => value,
 ) {
   const eventChain = usingEvent
-    ? `$event.${[...propertyParts, propertyName].join('.')}`
+    ? `event.${[...propertyParts, propertyName].join('.')}`
     : [...propertyParts, propertyName].join('.');
   return `${variableName}.setProperty(runtime, "${propertyName}", ${valueMapper(
     eventChain,
@@ -156,7 +156,7 @@ function generateArraySetter(
   usingEvent: boolean,
 ): string {
   const eventChain = usingEvent
-    ? `$event.${[...propertyParts, propertyName].join('.')}`
+    ? `event.${[...propertyParts, propertyName].join('.')}`
     : [...propertyParts, propertyName].join('.');
   const indexVar = `${propertyName}Index`;
   const innerLoopVar = `${propertyName}Value`;
@@ -376,14 +376,14 @@ function generateEvent(
 
   if (event.typeAnnotation.argument) {
     const implementation = `
-    auto $payload = jsi::Object(runtime);
+    auto payload = jsi::Object(runtime);
     ${generateSetters(
-      '$payload',
+      'payload',
       event.typeAnnotation.argument.properties,
       [],
       extraIncludes,
     )}
-    return $payload;
+    return payload;
   `.trim();
 
     if (!event.name.startsWith('on')) {