From 535e88b092838ac628232b19bb4728e17efc08ed Mon Sep 17 00:00:00 2001
From: Andrew Kolos <andrewrkolos@gmail.com>
Date: Wed, 31 Jul 2024 16:15:17 -0700
Subject: [PATCH] Reintroduce verbose logging for hot reload flake (#152639)

Adds some logging to assist with troubleshooting https://github.com/flutter/flutter/issues/152220 (which is a reapperance of flake https://github.com/flutter/flutter/issues/146879) on CI.

TL;DR [the tool sometimes never receives the `IsolateRunnable` event from the vm service after calling `_flutter.runInView`](https://github.com/flutter/flutter/issues/146879#issuecomment-2118629953).
---
 packages/flutter_tools/lib/src/run_hot.dart   |  9 ---------
 packages/flutter_tools/lib/src/vmservice.dart | 20 +++++++++++++++++++
 .../test/general.shard/vmservice_test.dart    |  2 +-
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/packages/flutter_tools/lib/src/run_hot.dart b/packages/flutter_tools/lib/src/run_hot.dart
index 2684e093b56..c73e578df0e 100644
--- a/packages/flutter_tools/lib/src/run_hot.dart
+++ b/packages/flutter_tools/lib/src/run_hot.dart
@@ -643,14 +643,6 @@ class HotRunner extends ResidentRunner {
         final Future<vm_service.Isolate?> reloadIsolate = device.vmService!
           .getIsolateOrNull(view.uiIsolate!.id!);
         operations.add(reloadIsolate.then((vm_service.Isolate? isolate) async {
-          // TODO(andrewkolos): this race is meant to assist in debugging
-          // https://github.com/flutter/flutter/issues/145812. When the issue
-          // is resolved, this trace (and probably all others added by
-          // the same PR) can be removed.
-          globals.logger.printTrace(
-            'Beginning of UI start paused handler. '
-            'uiIsolate = $isolate; isolate.pauseEvent.kind = ${isolate?.pauseEvent!.kind}',
-          );
           if ((isolate != null) && isPauseEvent(isolate.pauseEvent!.kind!)) {
             // The embedder requires that the isolate is unpaused, because the
             // runInView method requires interaction with dart engine APIs that
@@ -673,7 +665,6 @@ class HotRunner extends ResidentRunner {
             await Future.wait(breakpointAndExceptionRemoval);
             await device.vmService!.service.resume(view.uiIsolate!.id!);
           }
-          globals.logger.printTrace('End of UI start paused handler.');
         }));
       }
 
diff --git a/packages/flutter_tools/lib/src/vmservice.dart b/packages/flutter_tools/lib/src/vmservice.dart
index 196994c8b36..df5c969f42b 100644
--- a/packages/flutter_tools/lib/src/vmservice.dart
+++ b/packages/flutter_tools/lib/src/vmservice.dart
@@ -578,6 +578,25 @@ class FlutterVmService {
       }
     }
 
+    // TODO(andrewkolos): this is to assist in troubleshooting
+    //  https://github.com/flutter/flutter/issues/152220 and should be reverted
+    //  once this issue is resolved.
+    final StreamSubscription<String> onReceiveSubscription = service.onReceive.listen(
+      (String message) {
+        globals.logger.printTrace(
+          'runInView VM service onReceive listener received "$message"',
+        );
+        final dynamic messageAsJson = jsonDecode(message);
+        // ignore: avoid_dynamic_calls -- Temporary code.
+        final dynamic messageKind = messageAsJson['params']?['event']?['kind'];
+        if (messageKind == 'IsolateRunnable') {
+          globals.logger.printTrace(
+            'Received IsolateRunnable event from onReceive.',
+          );
+        }
+      },
+    );
+
     final Future<void> onRunnable = service.onIsolateEvent.firstWhere((vm_service.Event event) {
       return event.kind == vm_service.EventKind.kIsolateRunnable;
     });
@@ -590,6 +609,7 @@ class FlutterVmService {
       },
     );
     await onRunnable;
+    await onReceiveSubscription.cancel();
   }
 
   Future<String> flutterDebugDumpApp({
diff --git a/packages/flutter_tools/test/general.shard/vmservice_test.dart b/packages/flutter_tools/test/general.shard/vmservice_test.dart
index 951529364f3..683ebeef75e 100644
--- a/packages/flutter_tools/test/general.shard/vmservice_test.dart
+++ b/packages/flutter_tools/test/general.shard/vmservice_test.dart
@@ -231,7 +231,7 @@ void main() {
     });
   });
 
-  testWithoutContext('runInView forwards arguments correctly', () async {
+  testUsingContext('runInView forwards arguments correctly', () async {
     final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(
       requests: <VmServiceExpectation>[
         const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{