From 9e3842d624b1a58a86cf5d9f5192a5d8dac9c5b6 Mon Sep 17 00:00:00 2001
From: Paul Berry <paulberry@google.com>
Date: Wed, 30 May 2018 20:50:24 +0000
Subject: [PATCH] Observatory strong mode fix: fix type errors with
 onDisconnect.

The method ObservatoryApplication._switchVM calls newVM.onDisconnect
and requires the resulting future to be completed with a String.  In
normal operation, this is satisfied and we just need to change a few
static types to enforce it.  But when FakeVM was in use, the future
was completed with `this`.  Since ObservatoryApplication._switchVM is
the only call site that cares what the future is completed with, it
makes sense to just change all the types to Future<String> and modify
FakeVM accordingly.

Change-Id: Id94d27ac6a42f31ab19ccc9ad8dd270ecf4042b4
Reviewed-on: https://dart-review.googlesource.com/57400
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
---
 runtime/observatory/lib/service_common.dart     | 4 ++--
 runtime/observatory/lib/src/service/object.dart | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/runtime/observatory/lib/service_common.dart b/runtime/observatory/lib/service_common.dart
index d023f6e20ab..c2166c1e900 100644
--- a/runtime/observatory/lib/service_common.dart
+++ b/runtime/observatory/lib/service_common.dart
@@ -77,7 +77,7 @@ abstract class CommonWebSocket {
 /// The Dart VM can be embedded in Chromium or standalone.
 abstract class CommonWebSocketVM extends VM {
   final Completer _connected = new Completer();
-  final Completer _disconnected = new Completer<String>();
+  final Completer<String> _disconnected = new Completer<String>();
   final WebSocketVMTarget target;
   final Map<String, _WebSocketRequest> _delayedRequests =
       new Map<String, _WebSocketRequest>();
@@ -114,7 +114,7 @@ abstract class CommonWebSocketVM extends VM {
     }
   }
 
-  Future get onDisconnect => _disconnected.future;
+  Future<String> get onDisconnect => _disconnected.future;
   bool get isDisconnected => _disconnected.isCompleted;
 
   void disconnect({String reason: 'WebSocket closed'}) {
diff --git a/runtime/observatory/lib/src/service/object.dart b/runtime/observatory/lib/src/service/object.dart
index 6c526773d3f..58503e14f87 100644
--- a/runtime/observatory/lib/src/service/object.dart
+++ b/runtime/observatory/lib/src/service/object.dart
@@ -963,7 +963,7 @@ abstract class VM extends ServiceObjectOwner implements M.VM {
   Future get onConnect;
 
   /// Completes when the VM disconnects or there was an error connecting.
-  Future get onDisconnect;
+  Future<String> get onDisconnect;
 
   void _update(Map map, bool mapIsRef) {
     name = map['name'];
@@ -1047,7 +1047,7 @@ class FakeVM extends VM {
 
   /// Force the VM to disconnect.
   void disconnect() {
-    _onDisconnect.complete(this);
+    _onDisconnect.complete('Disconnected');
   }
 
   // Always connected.
@@ -1062,8 +1062,8 @@ class FakeVM extends VM {
 
   bool get isConnected => !isDisconnected;
   // Only complete when requested.
-  Completer _onDisconnect = new Completer();
-  Future get onDisconnect => _onDisconnect.future;
+  Completer<String> _onDisconnect = new Completer<String>();
+  Future<String> get onDisconnect => _onDisconnect.future;
   bool get isDisconnected => _onDisconnect.isCompleted;
 
   Future<Map> invokeRpcRaw(String method, Map params) {