Clean up the streamer.onmessage handler

- Fix "single player mode" filtering of highlights. It was assuming
  that $scope.persona was an object rather than a string.
- Remove multiple checks to ensure that payload is an array, the
  backend only sends arrays[1][2].
- Convert python style method docstrings to coffeescript comments.

[1]: https://github.com/hypothesis/h/blob/master/h/streamer.py#L562
[2]: https://github.com/hypothesis/h/blob/master/h/streamer.py#L488

h/static/scripts/controllers.coffee

@@ -17,7 +17,7 @@ class AppController
     isFirstRun = $location.search().hasOwnProperty('firstrun')
 
     applyUpdates = (action, data) ->
-      """Update the application with new data from the websocket."""
+      # Update the application with new data from the websocket.
       return unless data?.length
       if action == 'past'
         action = 'create'
@@ -32,28 +32,21 @@ class AppController
             plugins.Store?.unregisterAnnotation(annotation)
             annotator.deleteAnnotation(annotation)
 
-    streamer.onmessage = (msg) ->
-      data = msg.data
-      unless data.type? and data.type is 'annotation-notification'
+    streamer.onmessage = (data) ->
+      if !data or data.type != 'annotation-notification'
         return
 
-      payload = data.payload
       action = data.options.action
-
-      unless payload instanceof Array then payload = [payload]
-
-      p = auth.user
-      user = if p? then "acct:" + p.username + "@" + p.provider else ''
-      unless payload instanceof Array then payload = [payload]
+      payload = data.payload
 
       if $scope.socialView.name is 'single-player'
-        payload = payload.filter (d) -> d.user is user
+        payload = payload.filter (ann) -> ann.user is auth.user
 
-      applyUpdates action, payload
+      applyUpdates(action, payload)
       $scope.$digest()
 
     initStore = ->
-      """Initialize the storage component."""
+      # Initialize the storage component.
       Store = plugins.Store
       delete plugins.Store
 

h/static/scripts/streamer-service.coffee

@@ -59,7 +59,7 @@ class Streamer
       setTimeout((-> self.open()), backoff(self._failCount, 10))
 
     this._sock.onmessage = (msg) ->
-      self.onmessage(JSON.parse(msg))
+      self.onmessage(JSON.parse(msg.data))
 
   ###*
   # @ngdoc method

tests/js/streamer-service-test.coffee

@@ -107,14 +107,14 @@ describe 'streamer', ->
     clock.tick(500)
     assert.calledOnce(WebSocket)
 
-  it 'calls the onmessage handler when the socket recieves a message', ->
+  it 'calls the onmessage handler when the socket receives a message', ->
     streamer.onmessage = sinon.spy()
     streamer.open()
-    fakeSock.onmessage(JSON.stringify({animal: 'baboon'}))
+    fakeSock.onmessage(data: JSON.stringify({animal: 'baboon'}))
     assert.called(streamer.onmessage)
 
   it 'calls the onmessage handler with parsed JSON', ->
     streamer.onmessage = sinon.spy()
     streamer.open()
-    fakeSock.onmessage(JSON.stringify({animal: 'baboon'}))
+    fakeSock.onmessage(data: JSON.stringify({animal: 'baboon'}))
     assert.calledWith(streamer.onmessage, {animal: 'baboon'})