Support reconnects on page refreshes for SSE client connections

dwds/CHANGELOG.md

@@ -5,6 +5,8 @@
 - Fix pausing starting of `main` after the hot restart.
 - Updating bootstrapper for DDC library bundler module format + Frontend Server.
 - Fix setting up breakpoints when handling in-app restarts with attached debugger.
+- Fix setting up breakpoints when handling full reloads from attached
+  debugger / page refreshes.
 
 ## 26.2.2
 

dwds/lib/src/handlers/dev_handler.dart

@@ -636,21 +636,11 @@ class DevHandler {
       readyToRunMainCompleter.future,
     );
 
-    // We can take over a connection if there is no connectedInstanceId (this
-    // means the client completely disconnected), or if the existing
-    // AppConnection is in the KeepAlive state (this means it disconnected but
-    // is still waiting for a possible reconnect - this happens during a page
-    // reload).
-    final canReconnect =
-        services != null &&
-        (services.connectedInstanceId == null ||
-            existingConnection?.isInKeepAlivePeriod == true);
-
-    if (canReconnect) {
+    if (_canReconnect(existingConnection, message)) {
       // Disconnect any old connection (eg. those in the keep-alive waiting
       // state when reloading the page).
       existingConnection?.shutDown();
-      final chromeProxy = services.proxyService;
+      final chromeProxy = services!.proxyService;
       if (chromeProxy is ChromeProxyService) {
         chromeProxy.destroyIsolate();
       }
@@ -703,24 +693,10 @@ class DevHandler {
       readyToRunMainCompleter.future,
     );
 
-    // Allow connection reuse for page refreshes and same instance reconnections
-    final isSameInstance =
-        existingConnection?.request.instanceId == message.instanceId;
-    final isKeepAliveReconnect =
-        existingConnection?.isInKeepAlivePeriod == true;
-    final hasNoActiveConnection = services?.connectedInstanceId == null;
-    final noExistingConnection = existingConnection == null;
-
-    final canReconnect =
-        services != null &&
-        (isSameInstance ||
-            (isKeepAliveReconnect && hasNoActiveConnection) ||
-            (noExistingConnection && hasNoActiveConnection));
-
-    if (canReconnect) {
+    if (_canReconnect(existingConnection, message)) {
       // Reconnect to existing service.
       await _reconnectToService(
-        services,
+        services!,
         existingConnection,
         connection,
         message,
@@ -749,6 +725,30 @@ class DevHandler {
     return connection;
   }
 
+  /// Allow connection reuse for page refreshes and same instance reconnections
+  bool _canReconnect(
+    AppConnection? existingConnection,
+    ConnectRequest message,
+  ) {
+    final services = _servicesByAppId[message.appId];
+
+    if (services == null) {
+      return false;
+    }
+
+    if (existingConnection?.request.instanceId == message.instanceId) {
+      return true;
+    }
+
+    final isKeepAliveReconnect =
+        existingConnection?.isInKeepAlivePeriod == true;
+    final hasNoActiveConnection = services.connectedInstanceId == null;
+    final noExistingConnection = existingConnection == null;
+
+    return (isKeepAliveReconnect && hasNoActiveConnection) ||
+        (noExistingConnection && hasNoActiveConnection);
+  }
+
   /// Handles reconnection to existing services for web-socket mode.
   Future<void> _reconnectToService(
     AppDebugServices services,

dwds/web/client.dart

@@ -47,7 +47,22 @@ Future<void>? main() {
     () async {
       // Set the unique id for this instance of the app.
       // Test apps may already have this set.
-      dartAppInstanceId ??= const Uuid().v1();
+      const dartAppInstanceIdKey = 'dartAppInstanceId';
+      if (dartAppInstanceId == null) {
+        // Check the session storage for the instance id.
+        final storedInstanceId = window.sessionStorage.getItem(
+          dartAppInstanceIdKey,
+        );
+        if (storedInstanceId != null) {
+          dartAppInstanceId = storedInstanceId;
+        } else {
+          dartAppInstanceId = const Uuid().v1();
+          window.sessionStorage.setItem(
+            dartAppInstanceIdKey,
+            dartAppInstanceId!,
+          );
+        }
+      }
 
       final fixedPath = _fixProtocol(dwdsDevHandlerPath);
       final fixedUri = Uri.parse(fixedPath);