Switch to telling SseHandler to shutdown instead of closing each conn…

…ection

This allows bypassing the keep-alive period and fixes dart-lang#950.

dwds/debug_extension/pubspec.yaml

@@ -14,7 +14,7 @@ dependencies:
   js: ^0.6.1+1
   pedantic: ^1.5.0
   pub_semver: ^1.3.2
-  sse: ^3.2.0
+  sse: ^3.5.0
 
 dev_dependencies:
   webdev: ^2.0.0

dwds/lib/src/handlers/dev_handler.dart

@@ -91,11 +91,7 @@ class DevHandler {
 
   Future<void> close() => _closed ??= () async {
         await _sub.cancel();
-        // We listen for connections to close and remove them from the connections
-        // set. Therefore we shouldn't asynchronously iterate through the
-        // connections.
-        await Future.wait(_injectedConnections
-            .map((injectedConnection) => injectedConnection.sink.close()));
+        _sseHandler.shutdown();
         await Future.wait(_servicesByAppId.values.map((service) async {
           await service.close();
         }));

dwds/pubspec.yaml

@@ -31,7 +31,7 @@ dependencies:
   shelf_static: ^0.2.8
   shelf_web_socket: ^0.2.0
   source_maps: ^0.10.0
-  sse: ^3.2.0
+  sse: ^3.5.0
   vm_service: 4.0.0
   web_socket_channel: ^1.0.0
   webkit_inspection_protocol: '>=0.5.0+1 <0.6.0'

dwds/test/fixtures/fakes.dart

@@ -122,6 +122,9 @@ class FakeSseConnection implements SseConnection {
   StreamChannel<String> transformStream(
           StreamTransformer<String, String> transformer) =>
       null;
+
+  @override
+  void shutdown() {}
 }
 
 class FakeWebkitDebugger implements WebkitDebugger {

webdev/pubspec.yaml

@@ -28,7 +28,7 @@ dependencies:
   shelf: ^0.7.4
   shelf_proxy: ^0.1.0+5
   shelf_static: ^0.2.8
-  sse: ^3.2.0
+  sse: ^3.5.0
   vm_service: '>=3.0.0 <5.0.0'
   webkit_inspection_protocol: '>=0.4.0 <0.6.0'
   yaml: ^2.1.13