From 403bbae1f2483bc442dcc8f7f370a7b8e7155417 Mon Sep 17 00:00:00 2001
From: Moti Zilberman <moti@meta.com>
Date: Wed, 10 Apr 2024 04:04:12 -0700
Subject: [PATCH] Stub support for Tracing start/end methods and events
 (#44004)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/44004

Changelog: [Internal]

Adds the minimal boilerplate needed to support taking an (empty) recording using Chrome DevTools's Performance panel.

Reviewed By: hoxyq

Differential Revision: D55925170

fbshipit-source-id: 8f5048bd545be3ef410b794573ef7b7bc92f73cc
---
 .../jsinspector-modern/HostAgent.cpp          | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/packages/react-native/ReactCommon/jsinspector-modern/HostAgent.cpp b/packages/react-native/ReactCommon/jsinspector-modern/HostAgent.cpp
index 5d9ddda55be..bbbe14edf76 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/HostAgent.cpp
+++ b/packages/react-native/ReactCommon/jsinspector-modern/HostAgent.cpp
@@ -116,6 +116,26 @@ void HostAgent::handleRequest(const cdp::PreparsedRequest& req) {
 
     shouldSendOKResponse = true;
     isFinishedHandlingRequest = true;
+  } else if (req.method == "Tracing.start") {
+    // @cdp Tracing.start is implemented as a stub only.
+    frontendChannel_(cdp::jsonNotification(
+        // @cdp Tracing.bufferUsage is implemented as a stub only.
+        "Tracing.bufferUsage",
+        folly::dynamic::object("percentFull", 0)("eventCount", 0)("value", 0)));
+    shouldSendOKResponse = true;
+    isFinishedHandlingRequest = true;
+  } else if (req.method == "Tracing.end") {
+    // @cdp Tracing.end is implemented as a stub only.
+    frontendChannel_(cdp::jsonNotification(
+        // @cdp Tracing.dataCollected is implemented as a stub only.
+        "Tracing.dataCollected",
+        folly::dynamic::object("value", folly::dynamic::array())));
+    frontendChannel_(cdp::jsonNotification(
+        // @cdp Tracing.tracingComplete is implemented as a stub only.
+        "Tracing.tracingComplete",
+        folly::dynamic::object("dataLossOccurred", false)));
+    shouldSendOKResponse = true;
+    isFinishedHandlingRequest = true;
   }
 
   if (!isFinishedHandlingRequest && instanceAgent_ &&