Simplify retry and retry immediately

.gitignore

@@ -4,6 +4,7 @@
 build/
 packages
 # Remove the following pattern if you wish to check in your lock file
+pubspec.lock
 pubspec.lock.old
 
 # Files created by dart2js

lib/eventsource.dart

@@ -109,29 +109,31 @@ class EventSource extends Stream<Event> {
     }
     _readyState = EventSourceReadyState.OPEN;
     // start streaming the data
-    response.stream.transform(_decoder).listen((Event event) {
-      _streamController.add(event);
-      _lastEventId = event.id;
-    },
+    response.stream.transform(_decoder).listen(
+        (Event event) {
+          _streamController.add(event);
+          _lastEventId = event.id;
+        },
         cancelOnError: true,
-        onError: _retry,
+        onError: (err) {
+          _streamController.addError(err);
+          _retry();
+        },
         onDone: () => _readyState = EventSourceReadyState.CLOSED);
   }
 
   /// Retries until a new connection is established. Uses exponential backoff.
-  Future _retry(dynamic e) async {
-    _readyState = EventSourceReadyState.CONNECTING;
-    // try reopening with exponential backoff
+  Future _retry() async {
     Duration backoff = _retryDelay;
     while (true) {
-      await new Future.delayed(backoff);
       try {
         await _start();
         break;
       } catch (error) {
         _streamController.addError(error);
-        backoff *= 2;
       }
+      await new Future.delayed(backoff);
+      backoff *= 2;
     }
   }