Merge pull request #47 from hypothesis/fix-double-highlight

Avoid double highlighting

h/static/scripts/annotator/plugin/cross-frame.coffee

@@ -31,6 +31,7 @@ module.exports = class CrossFrame extends Annotator.Plugin
     this.destroy = ->
       # super doesnt work here :(
       Annotator.Plugin::destroy.apply(this, arguments)
+      bridge.destroy()
       discovery.stopDiscovery()
 
     this.sync = (annotations, cb) ->

h/static/scripts/annotator/plugin/test/cross-frame-test.coffee

@@ -19,6 +19,7 @@ describe 'Annotator.Plugin.CrossFrame', ->
       stopDiscovery: sandbox.stub()
 
     fakeBridge =
+      destroy: sandbox.stub()
       createChannel: sandbox.stub()
       onConnect: sandbox.stub()
       call: sandbox.stub()
@@ -75,10 +76,15 @@ describe 'Annotator.Plugin.CrossFrame', ->
 
   describe '.destroy', ->
     it 'stops the discovery of new frames', ->
-      bridge = createCrossFrame()
-      bridge.destroy()
+      cf = createCrossFrame()
+      cf.destroy()
       assert.called(fakeDiscovery.stopDiscovery)
 
+    it 'destroys the bridge object', ->
+      cf = createCrossFrame()
+      cf.destroy()
+      assert.called(fakeBridge.destroy)
+
   describe '.sync', ->
     it 'syncs the annotations with the other frame', ->
       bridge = createCrossFrame()

h/static/scripts/bridge.coffee

@@ -14,6 +14,13 @@ module.exports = class Bridge
     @channelListeners = {}
     @onConnectListeners = []
 
+  # Tear down the bridge. We destroy each RPC "channel" object we know about.
+  # This removes the `onmessage` event listeners, thus removing references to
+  # any listeners and allowing them to be garbage collected.
+  destroy: ->
+    for link in @links
+      link.channel.destroy()
+
   createChannel: (source, origin, token) ->
     channel = null
     connected = false

h/static/scripts/test/bridge-test.coffee

@@ -190,3 +190,15 @@ describe 'Bridge', ->
       bridge.onConnect(callback)
       bridge.onConnect(callback)
       channel = createChannel()
+
+  describe '.destroy', ->
+    it 'destroys all opened channels', ->
+      channel1 = bridge.createChannel(fakeWindow, 'http://example.com', 'foo')
+      channel2 = bridge.createChannel(fakeWindow, 'http://example.com', 'bar')
+      sinon.spy(channel1, 'destroy')
+      sinon.spy(channel2, 'destroy')
+
+      bridge.destroy()
+
+      assert.called(channel1.destroy)
+      assert.called(channel2.destroy)