fix[ReactDevTools]: wrap sendMessage expressions in setTimeout (#113)

Author: hoxyq

front_end/models/react_native/ReactDevToolsBindingsModel.ts

@@ -161,8 +161,14 @@ export class ReactDevToolsBindingsModel extends SDK.SDKModel.SDKModel {
     }
 
     const serializedMessage = JSON.stringify(message);
-
-    await runtimeModel.agent.invoke_evaluate({expression: `${RUNTIME_GLOBAL}.sendMessage('${domainName}', '${serializedMessage}')`});
+    const sendMessageExpression = `${RUNTIME_GLOBAL}.sendMessage('${domainName}', '${serializedMessage}')`;
+
+    // As of today, all expressions which were scheduled via Runtime.evaluate method are not going through RuntimeScheduler
+    // This means that the task is not being placed on the Event Loop, and any transitively called Microtasks are not executed properly
+    // We are wrapping the expression in setTimeout to make sure that this code (and everything what is called by it) goes through the Event Loop implementation
+    // See T200616136 for more context
+    // TODO(hoxyq): remove setTimeout once Runtime.evaluate expressions are passed through React Native Runtime Scheduler
+    await runtimeModel.agent.invoke_evaluate({expression: `void setTimeout(() => ${sendMessageExpression}, 0)`});
   }
 
   async enable(): Promise<void> {