Switch out jschannel for frame-rpc

The frame-rpc module is a proper CommonJS module and it's footprint
is really tiny. Its protocol is simpler. It doesn't handle connection
and buffering, but with our onConnect callback we don't need buffering.
The connection handshake that jschannel did was so trivial it's been
re-implemented here (each side tries to connect to the other once).

We have to handle timeouts ourselves, but that's all hidden in the
bridge code. In exchange, we get a simpler API, we get rid of the
call/notify distinction in favor of just passing a callback or not
and we avoid the excess overhead of the recursion guard in the
serialization code that was giving us false positive issues with
the document title.

This is one step toward removing all the browserify-shim requiring
libraries from the injected bundle, which will eventually fix #2397.

h/static/scripts/annotation-sync.coffee

@@ -58,49 +58,47 @@ module.exports = class AnnotationSync
   getAnnotationForTag: (tag) ->
     @cache[tag] or null
 
-  sync: (annotations, cb) ->
+  sync: (annotations) ->
     annotations = (this._format a for a in annotations)
-    @bridge.call
-      method: 'sync'
-      params: annotations
-      callback: cb
+    @bridge.call 'sync', annotations, (err, annotations = []) =>
+      for a in annotations
+        this._parse(a)
     this
 
   # Handlers for messages arriving through a channel
   _channelListeners:
-    'beforeCreateAnnotation': (txn, body) ->
+    'beforeCreateAnnotation': (body, cb) ->
       annotation = this._parse(body)
       delete @cache[annotation.$$tag]
       @_emit 'beforeAnnotationCreated', annotation
       @cache[annotation.$$tag] = annotation
-      this._format annotation
+      cb(null, this._format(annotation))
 
-    'createAnnotation': (txn, body) ->
+    'createAnnotation': (body, cb) ->
       annotation = this._parse(body)
       delete @cache[annotation.$$tag]
       @_emit 'annotationCreated', annotation
       @cache[annotation.$$tag] = annotation
-      this._format annotation
+      cb(null, this._format(annotation))
 
-    'updateAnnotation': (txn, body) ->
+    'updateAnnotation': (body, cb) ->
       annotation = this._parse(body)
       delete @cache[annotation.$$tag]
       @_emit('beforeAnnotationUpdated', annotation)
       @_emit('annotationUpdated', annotation)
       @cache[annotation.$$tag] = annotation
-      this._format annotation
+      cb(null, this._format(annotation))
 
-    'deleteAnnotation': (txn, body) ->
+    'deleteAnnotation': (body, cb) ->
       annotation = this._parse(body)
       delete @cache[annotation.$$tag]
       @_emit('annotationDeleted', annotation)
-      res = this._format(annotation)
-      res
+      cb(null, this._format(annotation))
 
-    'sync': (ctx, bodies) ->
-      (this._format(this._parse(b)) for b in bodies)
+    'sync': (bodies, cb) ->
+      cb(null, (this._format(this._parse(b)) for b in bodies))
 
-    'loadAnnotations': (txn, bodies) ->
+    'loadAnnotations': (bodies) ->
       annotations = (this._parse(a) for a in bodies)
       @_emit('loadAnnotations', annotations)
 
@@ -127,17 +125,13 @@ module.exports = class AnnotationSync
     'annotationsLoaded': (annotations) ->
       bodies = (this._format a for a in annotations when not a.$$tag)
       return unless bodies.length
-      @bridge.notify
-        method: 'loadAnnotations'
-        params: bodies
+      @bridge.call('loadAnnotations', bodies)
 
   _syncCache: (channel) ->
     # Synchronise (here to there) the items in our cache
     annotations = (this._format a for t, a of @cache)
     if annotations.length
-      channel.notify
-        method: 'loadAnnotations'
-        params: annotations
+      channel.call('loadAnnotations', annotations)
 
   _mkCallRemotelyAndParseResults: (method, callBack) ->
     (annotation) =>
@@ -148,11 +142,7 @@ module.exports = class AnnotationSync
         callBack? failure, results
 
       # Call the remote method
-      options =
-        method: method
-        callback: wrappedCallback
-        params: this._format(annotation)
-      @bridge.call(options)
+      @bridge.call(method, this._format(annotation), wrappedCallback)
 
   # Parse returned message bodies to update cache with any changes made remotely
   _parseResults: (results) ->

h/static/scripts/annotation-ui-sync.coffee

@@ -18,18 +18,18 @@ module.exports = class AnnotationUISync
       tags.map(annotationSync.getAnnotationForTag, annotationSync)
 
     channelListeners =
-      showAnnotations: (ctx, tags=[]) ->
+      showAnnotations: (tags=[]) ->
         annotations = getAnnotationsByTags(tags)
         annotationUI.selectAnnotations(annotations)
-      focusAnnotations: (ctx, tags=[]) ->
+      focusAnnotations: (tags=[]) ->
         annotations = getAnnotationsByTags(tags)
         annotationUI.focusAnnotations(annotations)
-      toggleAnnotationSelection: (ctx, tags=[]) ->
+      toggleAnnotationSelection: (tags=[]) ->
         annotations = getAnnotationsByTags(tags)
         annotationUI.xorSelectedAnnotations(annotations)
-      setVisibleHighlights: (ctx, state) ->
+      setVisibleHighlights: (state) ->
         annotationUI.visibleHighlights = Boolean(state)
-        bridge.notify(method: 'setVisibleHighlights', params: state)
+        bridge.call('setVisibleHighlights', state)
 
     # Because the channel events are all outside of the angular framework we
     # need to inform Angular that it needs to re-check it's state and re-draw
@@ -45,8 +45,6 @@ module.exports = class AnnotationUISync
     onConnect = (channel, source) ->
       # Allow the host to define its own state
       unless source is $window.parent
-        channel.notify
-          method: 'setVisibleHighlights'
-          params: annotationUI.visibleHighlights
+        channel.call('setVisibleHighlights', annotationUI.visibleHighlights)
 
     bridge.onConnect(onConnect)

h/static/scripts/annotator/guest.coffee

@@ -72,10 +72,6 @@ module.exports = class Guest extends Annotator
         formatted = {}
         for k, v of annotation when k isnt 'anchors'
           formatted[k] = v
-        # Work around issue in jschannel where a repeated object is considered
-        # recursive, even if it is not its own ancestor.
-        if formatted.document?.title
-          formatted.document.title = formatted.document.title.slice()
         formatted
 
     this.addPlugin('CrossFrame', cfOptions)
@@ -115,21 +111,20 @@ module.exports = class Guest extends Annotator
     crossframe.onConnect(=> this.publish('panelReady'))
     crossframe.on('onEditorHide', this.onEditorHide)
     crossframe.on('onEditorSubmit', this.onEditorSubmit)
-    crossframe.on 'focusAnnotations', (ctx, tags=[]) =>
+    crossframe.on 'focusAnnotations', (tags=[]) =>
       for anchor in @anchors when anchor.highlights?
         toggle = anchor.annotation.$$tag in tags
         $(anchor.highlights).toggleClass('annotator-hl-focused', toggle)
-    crossframe.on 'scrollToAnnotation', (ctx, tag) =>
+    crossframe.on 'scrollToAnnotation', (tag) =>
       for anchor in @anchors when anchor.highlights?
         if anchor.annotation.$$tag is tag
           $(anchor.highlights).scrollintoview()
           return
-    crossframe.on 'getDocumentInfo', (trans) =>
-      trans.delayReturn(true)
+    crossframe.on 'getDocumentInfo', (cb) =>
       this.getDocumentInfo()
-      .then((info) -> trans.complete(info))
-      .catch((reason) -> trans.error(reason))
-    crossframe.on 'setVisibleHighlights', (ctx, state) =>
+      .then((info) -> cb(null, info))
+      .catch((reason) -> cb(reason))
+    crossframe.on 'setVisibleHighlights', (state) =>
       this.publish 'setVisibleHighlights', state
 
   _setupWrapper: ->
@@ -315,24 +310,20 @@ module.exports = class Guest extends Annotator
     return annotation
 
   showAnnotations: (annotations) =>
-    @crossframe?.notify
-      method: "showAnnotations"
-      params: (a.$$tag for a in annotations)
+    tags = (a.$$tag for a in annotations)
+    @crossframe?.call('showAnnotations', tags)
 
   toggleAnnotationSelection: (annotations) =>
-    @crossframe?.notify
-      method: "toggleAnnotationSelection"
-      params: (a.$$tag for a in annotations)
+    tags = (a.$$tag for a in annotations)
+    @crossframe?.call('toggleAnnotationSelection', tags)
 
   updateAnnotations: (annotations) =>
-    @crossframe?.notify
-      method: "updateAnnotations"
-      params: (a.$$tag for a in annotations)
+    tags = (a.$$tag for a in annotations)
+    @crossframe?.call('updateAnnotations', tags)
 
   focusAnnotations: (annotations) =>
-    @crossframe?.notify
-      method: "focusAnnotations"
-      params: (a.$$tag for a in annotations)
+    tags = (a.$$tag for a in annotations)
+    @crossframe?.call('focusAnnotations', tags)
 
   onSuccessfulSelection: (event, immediate) ->
     unless event?
@@ -396,11 +387,7 @@ module.exports = class Guest extends Annotator
   # Pass true to show the highlights in the frame or false to disable.
   setVisibleHighlights: (shouldShowHighlights) ->
     return if @visibleHighlights == shouldShowHighlights
-
-    @crossframe?.notify
-      method: 'setVisibleHighlights'
-      params: shouldShowHighlights
-
+    @crossframe?.call('setVisibleHighlights', shouldShowHighlights)
     this.toggleHighlightClass(shouldShowHighlights)
 
   toggleHighlightClass: (shouldShowHighlights) ->
@@ -413,11 +400,11 @@ module.exports = class Guest extends Annotator
 
   # Open the sidebar
   showFrame: ->
-    @crossframe?.notify method: 'open'
+    @crossframe?.call('open')
 
   # Close the sidebar
   hideFrame: ->
-    @crossframe?.notify method: 'back'
+    @crossframe?.call('back')
 
   onAdderMouseup: (event) ->
     event.preventDefault()

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

@@ -12,7 +12,7 @@ extract = extract = (obj, keys...) ->
 # as keeping the annotation state in sync with the sidebar application, this
 # frame acts as the bridge client, the sidebar is the server. This plugin
 # can also be used to send messages through to the sidebar using the
-# notify method.
+# call method.
 module.exports = class CrossFrame extends Annotator.Plugin
   constructor: (elem, options) ->
     super
@@ -41,8 +41,8 @@ module.exports = class CrossFrame extends Annotator.Plugin
     this.on = (event, fn) ->
       bridge.on(event, fn)
 
-    this.notify = (message) ->
-      bridge.notify(message)
+    this.call = (message, args...) ->
+      bridge.call(message, args...)
 
     this.onConnect = (fn) ->
       bridge.onConnect(fn)

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

@@ -21,7 +21,7 @@ describe 'Annotator.Plugin.CrossFrame', ->
     fakeBridge =
       createChannel: sandbox.stub()
       onConnect: sandbox.stub()
-      notify: sandbox.stub()
+      call: sandbox.stub()
       on: sandbox.stub()
 
     fakeAnnotationSync =
@@ -91,11 +91,11 @@ describe 'Annotator.Plugin.CrossFrame', ->
       bridge.on('event', 'arg')
       assert.calledWith(fakeBridge.on, 'event', 'arg')
 
-  describe '.notify', ->
+  describe '.call', ->
     it 'proxies the call to the bridge', ->
       bridge = createCrossFrame()
-      bridge.notify(method: 'method')
-      assert.calledWith(fakeBridge.notify, method: 'method')
+      bridge.call('method', 'arg1', 'arg2')
+      assert.calledWith(fakeBridge.call, 'method', 'arg1', 'arg2')
 
   describe '.onConnect', ->
     it 'proxies the call to the bridge', ->

h/static/scripts/annotator/test/guest-test.coffee

@@ -144,18 +144,11 @@ describe 'Guest', ->
         formatted = options.formatter(ann)
         assert.equal(formatted.$$tag, 'tag1')
 
-      it 'strips the "anchors" property', ->
+      it 'strips properties that are not whitelisted', ->
         ann = {$$tag: 'tag1', anchors: []}
         formatted = options.formatter(ann)
         assert.notProperty(formatted, 'anchors')
 
-      it 'clones the document.title array if present', ->
-        title = ['Page Title']
-        ann = {$$tag: 'tag1', document: {title: title}}
-        formatted = options.formatter(ann)
-        assert.notStrictEqual(title, formatted.document.title)
-        assert.deepEqual(title, formatted.document.title)
-
   describe 'annotation UI events', ->
     emitGuestEvent = (event, args...) ->
       fn(args...) for [evt, fn] in fakeCrossFrame.on.args when event == evt
@@ -183,7 +176,7 @@ describe 'Guest', ->
           {annotation: {$$tag: 'tag1'}, highlights: highlight0.toArray()}
           {annotation: {$$tag: 'tag2'}, highlights: highlight1.toArray()}
         ]
-        emitGuestEvent('focusAnnotations', 'ctx', ['tag1'])
+        emitGuestEvent('focusAnnotations', ['tag1'])
         assert.isTrue(highlight0.hasClass('annotator-hl-focused'))
 
       it 'unfocuses any annotations without a matching tag', ->
@@ -210,7 +203,7 @@ describe 'Guest', ->
         guest.anchors = [
           {annotation: {$$tag: 'tag1'}, highlights: highlight.toArray()}
         ]
-        emitGuestEvent('scrollToAnnotation', 'ctx', 'tag1')
+        emitGuestEvent('scrollToAnnotation', 'tag1')
         assert.calledOn($.fn.scrollintoview, sinon.match(highlight))
 
     describe 'on "getDocumentInfo" event', ->
@@ -227,7 +220,7 @@ describe 'Guest', ->
         sandbox.restore()
 
       it 'calls the callback with the href and pdf metadata', (done) ->
-        assertComplete = (payload) ->
+        assertComplete = (err, payload) ->
           try
             assert.equal(payload.uri, document.location.href)
             assert.equal(payload.metadata, metadata)
@@ -235,15 +228,14 @@ describe 'Guest', ->
           catch e
             done(e)
 
-        ctx = {complete: assertComplete, delayReturn: sandbox.stub()}
         metadata = {title: 'hi'}
         promise = Promise.resolve(metadata)
         guest.plugins.PDF.getMetadata.returns(promise)
 
-        emitGuestEvent('getDocumentInfo', ctx)
+        emitGuestEvent('getDocumentInfo', assertComplete)
 
       it 'calls the callback with the href and basic metadata if pdf fails', (done) ->
-        assertComplete = (payload) ->
+        assertComplete = (err, payload) ->
           try
             assert.equal(payload.uri, window.location.href)
             assert.deepEqual(payload.metadata, metadata)
@@ -251,20 +243,11 @@ describe 'Guest', ->
           catch e
             done(e)
 
-        ctx = {complete: assertComplete, delayReturn: sandbox.stub()}
         metadata = {title: 'hi', link: [{href: window.location.href}]}
-
         promise = Promise.reject(new Error('Not a PDF document'))
         guest.plugins.PDF.getMetadata.returns(promise)
 
-        emitGuestEvent('getDocumentInfo', ctx)
-
-      it 'notifies the channel that the return value is async', ->
-        delete guest.plugins.PDF
-
-        ctx = {complete: sandbox.stub(), delayReturn: sandbox.stub()}
-        emitGuestEvent('getDocumentInfo', ctx)
-        assert.calledWith(ctx.delayReturn, true)
+        emitGuestEvent('getDocumentInfo', assertComplete)
 
   describe 'onAdderMouseUp', ->
     it 'it prevents the default browser action when triggered', () ->

h/static/scripts/annotator/test/host-test.coffee

@@ -16,7 +16,7 @@ describe 'Host', ->
     fakeCrossFrame = {}
     fakeCrossFrame.onConnect = sandbox.stub().returns(fakeCrossFrame)
     fakeCrossFrame.on = sandbox.stub().returns(fakeCrossFrame)
-    fakeCrossFrame.notify = sandbox.stub().returns(fakeCrossFrame)
+    fakeCrossFrame.call = sandbox.spy()
 
     Annotator.Plugin.CrossFrame = -> fakeCrossFrame
 

h/static/scripts/bridge.coffee

-$ = require('jquery')
-Channel = require('jschannel')
+extend = require('extend')
+RPC = require('frame-rpc')
 
 # The Bridge service sets up a channel between frames
 # and provides an events API on top of it.
@@ -14,20 +14,28 @@ module.exports = class Bridge
     @channelListeners = {}
     @onConnectListeners = []
 
-  createChannel: (source, origin, scope) ->
+  createChannel: (source, origin, token) ->
+    channel = null
+    connected = false
+
+    ready = =>
+      return if connected
+      connected = true
+      for cb in @onConnectListeners
+        cb.call(null, channel, source)
+
+    connect = (_token, cb) =>
+      if _token is token
+        cb()
+        ready()
+
+    listeners = extend({connect}, @channelListeners)
+
     # Set up a channel
-    channelOptions =
-      window: source
-      origin: origin
-      scope: scope
-      onReady: (channel) =>
-        for callback in @onConnectListeners
-          callback.call(this, channel, source)
-    channel = this._buildChannel channelOptions
+    channel = new RPC(window, source, origin, listeners)
 
-    # Attach channel message listeners
-    for own method, callback of @channelListeners
-      channel.bind method, callback
+    # Fire off a connection attempt
+    channel.call('connect', token, ready)
 
     # Store the newly created channel in our collection
     @links.push
@@ -38,55 +46,50 @@ module.exports = class Bridge
 
   # Make a method call on all links, collect the results and pass them to a
   # callback when all results are collected. Parameters:
-  # - options.method (required): name of remote method to call
-  # - options.params: parameters to pass to remote method
-  # - options.callback: called with array of results
-  call: (options) ->
+  # - method (required): name of remote method to call
+  # - args...: parameters to pass to remote method
+  # - callback: (optional) called with error, if any, and an Array of results
+  call: (method, args...) ->
+    cb = null
+    if typeof(args[args.length - 1]) is 'function'
+      cb = args[args.length - 1]
+      args = args.slice(0, -1)
+
     _makeDestroyFn = (c) =>
-      (error, reason) =>
+      (error) =>
         c.destroy()
         @links = (l for l in @links when l.channel isnt c)
+        throw error
 
-    deferreds = @links.map (l) ->
-      d = $.Deferred().fail(_makeDestroyFn l.channel)
-      callOptions = {
-        method: options.method
-        params: options.params
-        success: (result) -> d.resolve result
-        error: (error, reason) ->
-          if error isnt 'timeout_error'
-            d.reject error, reason
-          else
-            d.resolve null
-        timeout: 1000
-      }
-      l.channel.call callOptions
-      d.promise()
-
-    $.when(deferreds...)
-    .then (results...) =>
-      options.callback? null, results
-    .fail (failure) =>
-      options.callback? failure
-
-  # Publish a notification to all links
-  notify: (options) ->
-    for l in @links
-      l.channel.notify options
-    return
+    promises = @links.map (l) ->
+      p = new Promise (resolve, reject) ->
+        timeout = setTimeout((-> resolve(null)), 1000)
+        try
+          l.channel.call method, args..., (err, result) ->
+            clearTimeout(timeout)
+            if err then reject(err) else resolve(result)
+        catch err
+          reject(err)
+
+      # Don't assign here. The disconnect is handled asynchronously.
+      return p.catch(_makeDestroyFn(l.channel))
+
+    resultPromise = Promise.all(promises)
+
+    if cb?
+      resultPromise = resultPromise
+        .then((results) -> cb(null, results))
+        .catch((error) -> cb(error))
+
+    return resultPromise
 
   on: (method, callback) ->
     if @channelListeners[method]
       throw new Error("Listener '#{method}' already bound in Bridge")
-
     @channelListeners[method] = callback
-    for l in @links
-      l.channel.bind method, callback
     return this
 
   off: (method) ->
-    for l in @links
-      l.channel.unbind method
     delete @channelListeners[method]
     return this
 
@@ -94,11 +97,3 @@ module.exports = class Bridge
   onConnect: (callback) ->
     @onConnectListeners.push(callback)
     this
-
-  # Construct a channel to another frame
-  _buildChannel: (options) ->
-    # jschannel chokes on FF and Chrome extension origins.
-    if (options.origin.match /^chrome-extension:\/\//) or
-        (options.origin.match /^resource:\/\//)
-      options = $.extend {}, options, {origin: '*'}
-    channel = Channel.build(options)

h/static/scripts/cross-frame.coffee

@@ -45,9 +45,10 @@ module.exports = class CrossFrame
       new AnnotationUISync($rootScope, $window, bridge, annotationSync, annotationUI)
 
     addFrame = (channel) =>
-      channel.call
-        method: 'getDocumentInfo'
-        success: (info) =>
+      channel.call 'getDocumentInfo', (err, info) =>
+        if err
+          channel.destroy()
+        else
           $rootScope.$apply =>
             @frames.push({channel: channel, uri: info.uri})
 
@@ -62,6 +63,6 @@ module.exports = class CrossFrame
         bridge.createChannel(source, origin, token)
       discovery.startDiscovery(onDiscoveryCallback)
 
-      this.notify = bridge.notify.bind(bridge)
+      this.call = bridge.call.bind(bridge)
 
-    this.notify = -> throw new Error('connect() must be called before notify()')
+    this.call = -> throw new Error('connect() must be called before call()')

h/static/scripts/host.coffee

@@ -11,13 +11,13 @@ module.exports = [
   '$window', 'bridge'
   ($window,   bridge) ->
     host =
-      showSidebar: -> notifyHost method: 'showFrame'
-      hideSidebar: -> notifyHost method: 'hideFrame'
+      showSidebar: -> callHost('showFrame')
+      hideSidebar: -> callHost('hideFrame')
 
     # Sends a message to the host frame
-    notifyHost = (message) ->
+    callHost = (method) ->
       for {channel, window} in bridge.links when window is $window.parent
-        channel.notify(message)
+        channel.call(method)
         break
 
     channelListeners =

h/static/scripts/test/annotation-sync-test.coffee

@@ -5,7 +5,7 @@ describe 'AnnotationSync', ->
   publish = null
   fakeBridge = null
   createAnnotationSync = null
-  createChannel = -> {notify: sandbox.stub()}
+  createChannel = -> {call: sandbox.stub()}
   options = null
   PARENT_WINDOW = 'PARENT_WINDOW'
 
@@ -16,13 +16,12 @@ describe 'AnnotationSync', ->
   beforeEach module('h')
   beforeEach inject (AnnotationSync, $rootScope) ->
     listeners = {}
-    publish = ({method, params}) -> listeners[method]('ctx', params)
+    publish = (method, args...) -> listeners[method](args...)
 
     fakeWindow = parent: PARENT_WINDOW
     fakeBridge =
       on: sandbox.spy((method, fn) -> listeners[method] = fn)
       call: sandbox.stub()
-      notify: sandbox.stub()
       onConnect: sandbox.stub()
       links: []
 
@@ -47,11 +46,9 @@ describe 'AnnotationSync', ->
       channel = createChannel()
       fakeBridge.onConnect.yield(channel)
 
-      assert.called(channel.notify)
-      assert.calledWith(channel.notify, {
-        method: 'loadAnnotations'
-        params: [tag: 'tag1', msg: ann]
-      })
+      assert.called(channel.call)
+      assert.calledWith(channel.call, 'loadAnnotations',
+        [tag: 'tag1', msg: ann])
 
     it 'does nothing if the cache is empty', ->
       annSync = createAnnotationSync()
@@ -59,7 +56,7 @@ describe 'AnnotationSync', ->
       channel = createChannel()
       fakeBridge.onConnect.yield(channel)
 
-      assert.notCalled(channel.notify)
+      assert.notCalled(channel.call)
 
   describe '.getAnnotationForTag', ->
     it 'returns the annotation if present in the cache', ->
@@ -80,18 +77,20 @@ describe 'AnnotationSync', ->
       it 'broadcasts the "' + publishEvent + '" event over the local event bus', ->
         ann = {id: 1, $$tag: 'tag1'}
         annSync = createAnnotationSync()
-        publish(method: channelEvent, params: {msg: ann})
+        publish(channelEvent, {msg: ann}, ->)
         assert.called(options.emit)
         assert.calledWith(options.emit, publishEvent, ann)
 
     assertReturnValue = (channelEvent) ->
-      it 'returns a formatted annotation to be sent to the calling frame', ->
+      it 'calls back with a formatted annotation', (done) ->
         ann = {id: 1, $$tag: 'tag1'}
         annSync = createAnnotationSync()
 
-        ret = publish(method: channelEvent, params: {msg: ann})
-
+        callback = (err, ret) ->
+          assert.isNull(err)
           assert.deepEqual(ret, {tag: 'tag1', msg: ann})
+          done()
+        publish(channelEvent, {msg: ann}, callback)
 
     assertCacheState = (channelEvent) ->
       it 'removes an existing entry from the cache before the event is triggered', ->
@@ -101,13 +100,13 @@ describe 'AnnotationSync', ->
         annSync = createAnnotationSync()
         annSync.cache['tag1'] = ann
 
-        publish(method: channelEvent, params: {msg: ann})
+        publish(channelEvent, {msg: ann}, ->)
 
       it 'ensures the annotation is inserted in the cache', ->
         ann = {id: 1, $$tag: 'tag1'}
         annSync = createAnnotationSync()
 
-        publish(method: channelEvent, params: {msg: ann})
+        publish(channelEvent, {msg: ann}, ->)
 
         assert.equal(annSync.cache['tag1'], ann)
 
@@ -138,29 +137,33 @@ describe 'AnnotationSync', ->
         annSync = createAnnotationSync()
         annSync.cache['tag1'] = ann
 
-        publish(method: 'deleteAnnotation', params: {msg: ann})
+        publish('deleteAnnotation', {msg: ann}, ->)
 
       it 'removes the annotation from the cache', ->
         ann = {id: 1, $$tag: 'tag1'}
         annSync = createAnnotationSync()
 
-        publish(method: 'deleteAnnotation', params: {msg: ann})
+        publish('deleteAnnotation', {msg: ann}, ->)
 
         assert(!annSync.cache['tag1'])
 
     describe 'the "sync" event', ->
-      it 'returns an array of parsed and formatted annotations', ->
+      it 'calls back with parsed and formatted annotations', (done) ->
         options.parser = sinon.spy((x) -> x)
         options.formatter = sinon.spy((x) -> x)
         annSync = createAnnotationSync()
 
         annotations = [{id: 1, $$tag: 'tag1'}, {id: 2, $$tag: 'tag2'}, {id: 3, $$tag: 'tag3'}]
         bodies = ({msg: ann, tag: ann.$$tag} for ann in annotations)
-        ret = publish(method: 'sync', params: bodies)
 
-        assert.deepEqual(ret, ret)
+        callback = (err, ret) ->
+          assert.isNull(err)
+          assert.deepEqual(ret, bodies)
           assert.called(options.parser)
           assert.called(options.formatter)
+          done()
+
+        publish('sync', bodies, callback)
 
     describe 'the "loadAnnotations" event', ->
       it 'publishes the "loadAnnotations" event with parsed annotations', ->
@@ -169,7 +172,7 @@ describe 'AnnotationSync', ->
 
         annotations = [{id: 1, $$tag: 'tag1'}, {id: 2, $$tag: 'tag2'}, {id: 3, $$tag: 'tag3'}]
         bodies = ({msg: ann, tag: ann.$$tag} for ann in annotations)
-        ret = publish(method: 'loadAnnotations', params: bodies)
+        publish('loadAnnotations', bodies, ->)
 
         assert.called(options.parser)
         assert.calledWith(options.emit, 'loadAnnotations', annotations)
@@ -182,11 +185,8 @@ describe 'AnnotationSync', ->
         options.emit('beforeAnnotationCreated', ann)
 
         assert.called(fakeBridge.call)
-        assert.calledWith(fakeBridge.call, {
-          method: 'beforeCreateAnnotation',
-          params: {msg: ann, tag: ann.$$tag},
-          callback: sinon.match.func
-        })
+        assert.calledWith(fakeBridge.call, 'beforeCreateAnnotation',
+          {msg: ann, tag: ann.$$tag}, sinon.match.func)
 
       it 'returns early if the annotation has a tag', ->
         ann = {id: 1, $$tag: 'tag1'}
@@ -203,11 +203,8 @@ describe 'AnnotationSync', ->
         options.emit('annotationCreated', ann)
 
         assert.called(fakeBridge.call)
-        assert.calledWith(fakeBridge.call, {
-          method: 'createAnnotation',
-          params: {msg: ann, tag: ann.$$tag},
-          callback: sinon.match.func
-        })
+        assert.calledWith(fakeBridge.call, 'createAnnotation',
+          {msg: ann, tag: ann.$$tag}, sinon.match.func)
 
       it 'returns early if the annotation has a tag but is not cached', ->
         ann = {id: 1, $$tag: 'tag1'}
@@ -231,11 +228,8 @@ describe 'AnnotationSync', ->
         options.emit('annotationUpdated', ann)
 
         assert.called(fakeBridge.call)
-        assert.calledWith(fakeBridge.call, {
-          method: 'updateAnnotation',
-          params: {msg: ann, tag: ann.$$tag},
-          callback: sinon.match.func
-        })
+        assert.calledWith(fakeBridge.call, 'updateAnnotation',
+          {msg: ann, tag: ann.$$tag}, sinon.match.func)
 
       it 'returns early if the annotation has a tag but is not cached', ->
         ann = {id: 1, $$tag: 'tag1'}
@@ -259,11 +253,8 @@ describe 'AnnotationSync', ->
         options.emit('annotationDeleted', ann)
 
         assert.called(fakeBridge.call)
-        assert.calledWith(fakeBridge.call, {
-          method: 'deleteAnnotation',
-          params: {msg: ann, tag: ann.$$tag},
-          callback: sinon.match.func
-        })
+        assert.calledWith(fakeBridge.call, 'deleteAnnotation',
+          {msg: ann, tag: ann.$$tag}, sinon.match.func)
 
       it 'parses the result returned by the call', ->
         ann = {id: 1, $$tag: 'tag1'}
@@ -273,7 +264,7 @@ describe 'AnnotationSync', ->
         options.emit('annotationDeleted', ann)
 
         body = {msg: {}, tag: 'tag1'}
-        fakeBridge.call.yieldTo('callback', null, [body])
+        fakeBridge.call.yield(null, [body])
         assert.called(options.parser)
         assert.calledWith(options.parser, {})
 
@@ -283,7 +274,7 @@ describe 'AnnotationSync', ->
         annSync.cache.tag1 = ann
         options.emit('annotationDeleted', ann)
 
-        fakeBridge.call.yieldTo('callback', null, [])
+        fakeBridge.call.yield(null, [])
         assert.isUndefined(annSync.cache.tag1)
 
       it 'does not remove the annotation from the cache if an error occurs', ->
@@ -292,7 +283,7 @@ describe 'AnnotationSync', ->
         annSync.cache.tag1 = ann
         options.emit('annotationDeleted', ann)
 
-        fakeBridge.call.yieldTo('callback', new Error('Error'), [])
+        fakeBridge.call.yield(new Error('Error'), [])
         assert.equal(annSync.cache.tag1, ann)
 
       it 'returns early if the annotation has a tag but is not cached', ->
@@ -326,11 +317,9 @@ describe 'AnnotationSync', ->
         annSync = createAnnotationSync()
         options.emit('annotationsLoaded', annotations)
 
-        assert.called(fakeBridge.notify)
-        assert.calledWith(fakeBridge.notify, {
-          method: 'loadAnnotations',
-          params: {msg: a, tag: a.$$tag} for a in annotations
-        })
+        assert.called(fakeBridge.call)
+        assert.calledWith(fakeBridge.call, 'loadAnnotations',
+          ({msg: a, tag: a.$$tag} for a in annotations))
 
       it 'does not send annotations that have already been tagged', ->
         annotations = [{id: 1, $$tag: 'tag1'}, {id: 2, $$tag: 'tag2'}, {id: 3}]
@@ -338,14 +327,12 @@ describe 'AnnotationSync', ->
         annSync = createAnnotationSync()
         options.emit('annotationsLoaded', annotations)
 
-        assert.called(fakeBridge.notify)
-        assert.calledWith(fakeBridge.notify, {
-          method: 'loadAnnotations',
-          params: [{msg: annotations[2], tag: annotations[2].$$tag}]
-        })
+        assert.called(fakeBridge.call)
+        assert.calledWith(fakeBridge.call, 'loadAnnotations',
+          [{msg: annotations[2], tag: annotations[2].$$tag}])
 
       it 'returns early if no annotations are loaded', ->
         annSync = createAnnotationSync()
         options.emit('annotationsLoaded', [])
 
-        assert.notCalled(fakeBridge.notify)
+        assert.notCalled(fakeBridge.call)

h/static/scripts/test/annotation-ui-sync-test.coffee

@@ -9,7 +9,7 @@ describe 'AnnotationUISync', ->
   fakeAnnotationUI = null
   fakeAnnotationSync = null
   createAnnotationUISync = null
-  createChannel = -> {notify: sandbox.stub()}
+  createChannel = -> {call: sandbox.stub()}
   PARENT_WINDOW = 'PARENT_WINDOW'
 
   before ->
@@ -20,12 +20,12 @@ describe 'AnnotationUISync', ->
   beforeEach inject (AnnotationUISync, $rootScope) ->
     $digest = sandbox.stub($rootScope, '$digest')
     listeners = {}
-    publish = ({method, params}) -> listeners[method]('ctx', params)
+    publish = (method, args...) -> listeners[method](args...)
 
     fakeWindow = parent: PARENT_WINDOW
     fakeBridge =
       on: sandbox.spy((method, fn) -> listeners[method] = fn)
-      notify: sandbox.stub()
+      call: sandbox.stub()
       onConnect: sandbox.stub()
       links: [
         {window: PARENT_WINDOW,    channel: createChannel()}
@@ -54,26 +54,20 @@ describe 'AnnotationUISync', ->
 
         createAnnotationUISync()
 
-        assert.calledWith(channel.notify, {
-          method: 'setVisibleHighlights'
-          params: false
-        })
+        assert.calledWith(channel.call, 'setVisibleHighlights', false)
 
     describe 'when the source is the parent window', ->
       it 'does nothing', ->
-        channel = notify: sandbox.stub()
+        channel = call: sandbox.stub()
         fakeBridge.onConnect.callsArgWith(0, channel, PARENT_WINDOW)
 
         createAnnotationUISync()
-        assert.notCalled(channel.notify)
+        assert.notCalled(channel.call)
 
   describe 'on "showAnnotations" event', ->
     it 'updates the annotationUI to include the shown annotations', ->
       createAnnotationUISync()
-      publish({
-        method: 'showAnnotations',
-        params: ['tag1', 'tag2', 'tag3']
-      })
+      publish('showAnnotations', ['tag1', 'tag2', 'tag3'])
       assert.called(fakeAnnotationUI.selectAnnotations)
       assert.calledWith(fakeAnnotationUI.selectAnnotations, [
         {id: 1}, {id: 2}, {id: 3}
@@ -81,19 +75,13 @@ describe 'AnnotationUISync', ->
 
     it 'triggers a digest', ->
       createAnnotationUISync()
-      publish({
-        method: 'showAnnotations',
-        params: ['tag1', 'tag2', 'tag3']
-      })
+      publish('showAnnotations', ['tag1', 'tag2', 'tag3'])
       assert.called($digest)
 
   describe 'on "focusAnnotations" event', ->
     it 'updates the annotationUI to show the provided annotations', ->
       createAnnotationUISync()
-      publish({
-        method: 'focusAnnotations',
-        params: ['tag1', 'tag2', 'tag3']
-      })
+      publish('focusAnnotations', ['tag1', 'tag2', 'tag3'])
       assert.called(fakeAnnotationUI.focusAnnotations)
       assert.calledWith(fakeAnnotationUI.focusAnnotations, [
         {id: 1}, {id: 2}, {id: 3}
@@ -101,19 +89,13 @@ describe 'AnnotationUISync', ->
 
     it 'triggers a digest', ->
       createAnnotationUISync()
-      publish({
-        method: 'focusAnnotations',
-        params: ['tag1', 'tag2', 'tag3']
-      })
+      publish('focusAnnotations', ['tag1', 'tag2', 'tag3'])
       assert.called($digest)
 
   describe 'on "toggleAnnotationSelection" event', ->
     it 'updates the annotationUI to show the provided annotations', ->
       createAnnotationUISync()
-      publish({
-        method: 'toggleAnnotationSelection',
-        params: ['tag1', 'tag2', 'tag3']
-     })
+      publish('toggleAnnotationSelection', ['tag1', 'tag2', 'tag3'])
       assert.called(fakeAnnotationUI.xorSelectedAnnotations)
       assert.calledWith(fakeAnnotationUI.xorSelectedAnnotations, [
         {id: 1}, {id: 2}, {id: 3}
@@ -121,36 +103,21 @@ describe 'AnnotationUISync', ->
 
     it 'triggers a digest', ->
       createAnnotationUISync()
-      publish({
-        method: 'toggleAnnotationSelection',
-        params: ['tag1', 'tag2', 'tag3']
-      })
+      publish('toggleAnnotationSelection', ['tag1', 'tag2', 'tag3'])
       assert.called($digest)
 
   describe 'on "setVisibleHighlights" event', ->
     it 'updates the annotationUI with the new value', ->
       createAnnotationUISync()
-      publish({
-        method: 'setVisibleHighlights',
-        params: true
-      })
+      publish('setVisibleHighlights', true)
       assert.equal(fakeAnnotationUI.visibleHighlights, true)
 
     it 'notifies the other frames of the change', ->
       createAnnotationUISync()
-      publish({
-        method: 'setVisibleHighlights',
-        params: true
-      })
-      assert.calledWith(fakeBridge.notify, {
-        method: 'setVisibleHighlights'
-        params: true
-      })
+      publish('setVisibleHighlights', true)
+      assert.calledWith(fakeBridge.call, 'setVisibleHighlights', true)
 
     it 'triggers a digest of the application state', ->
       createAnnotationUISync()
-      publish({
-        method: 'setVisibleHighlights',
-        params: true
-      })
+      publish('setVisibleHighlights', true)
       assert.called($digest)

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

@@ -26,7 +26,7 @@ describe 'CrossFrame', ->
     fakeDiscovery =
       startDiscovery: sandbox.stub()
     fakeBridge =
-      notify: sandbox.stub()
+      call: sandbox.stub()
       createChannel: sandbox.stub()
       onConnect: sandbox.stub()
     fakeAnnotationSync = {}
@@ -61,28 +61,16 @@ describe 'CrossFrame', ->
 
     it 'queries discovered frames for metadata', ->
       uri = 'http://example.com'
-      channel = {call: sandbox.stub().yieldsTo('success', {uri: uri})}
+      channel = {call: sandbox.stub().yields(null, {uri: uri})}
       fakeBridge.onConnect.yields(channel)
       crossframe.connect()
-      assert.calledWith(channel.call, {
-        method: 'getDocumentInfo'
-        success: sinon.match.func
-      })
+      assert.calledWith(channel.call, 'getDocumentInfo', sinon.match.func)
 
     it 'updates the frames array', ->
       uri = 'http://example.com'
-      channel = {call: sandbox.stub().yieldsTo('success', {uri: uri})}
+      channel = {call: sandbox.stub().yields(null, {uri: uri})}
       fakeBridge.onConnect.yields(channel)
       crossframe.connect()
       assert.deepEqual(crossframe.frames, [
         {channel: channel, uri: uri}
       ])
-
-
-  describe '.notify()', ->
-    it 'proxies the call to the bridge', ->
-      message = {method: 'foo', params: 'bar'}
-      crossframe.connect() # create the bridge.
-      crossframe.notify(message)
-      assert.calledOn(fakeBridge.notify, fakeBridge)
-      assert.calledWith(fakeBridge.notify, message)

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

@@ -3,7 +3,7 @@
 describe 'host', ->
   sandbox = null
   host = null
-  createChannel = -> notify: sandbox.stub()
+  createChannel = -> call: sandbox.stub()
   fakeBridge = null
   $digest = null
   publish = null
@@ -22,13 +22,13 @@ describe 'host', ->
 
     listeners = {}
 
-    publish = ({method, params}) ->
-      listeners[method]('ctx', params)
+    publish = (method, args...) ->
+      listeners[method](args...)
 
     fakeBridge =
       ls: listeners
       on: sandbox.spy (method, fn) -> listeners[method] = fn
-      notify: sandbox.stub()
+      call: sandbox.stub()
       onConnect: sandbox.stub()
       links: [
         {window: PARENT_WINDOW,    channel: createChannel()}
@@ -53,16 +53,16 @@ describe 'host', ->
     describe 'showSidebar()', ->
       it 'sends the "showFrame" message to the host only', ->
         host.showSidebar()
-        assert.calledWith(fakeBridge.links[0].channel.notify, method: 'showFrame')
-        assert.notCalled(fakeBridge.links[1].channel.notify)
-        assert.notCalled(fakeBridge.links[2].channel.notify)
+        assert.calledWith(fakeBridge.links[0].channel.call, 'showFrame')
+        assert.notCalled(fakeBridge.links[1].channel.call)
+        assert.notCalled(fakeBridge.links[2].channel.call)
 
     describe 'hideSidebar()', ->
       it 'sends the "hideFrame" message to the host only', ->
         host.hideSidebar()
-        assert.calledWith(fakeBridge.links[0].channel.notify, method: 'hideFrame')
-        assert.notCalled(fakeBridge.links[1].channel.notify)
-        assert.notCalled(fakeBridge.links[2].channel.notify)
+        assert.calledWith(fakeBridge.links[0].channel.call, 'hideFrame')
+        assert.notCalled(fakeBridge.links[1].channel.call)
+        assert.notCalled(fakeBridge.links[2].channel.call)
 
   describe 'reacting to the bridge', ->
 
@@ -70,12 +70,12 @@ describe 'host', ->
 
       it 'triggers the hideSidebar() API', ->
         sandbox.spy host, "hideSidebar"
-        publish method: 'back'
+        publish 'back'
         assert.called host.hideSidebar
 
     describe 'on "open" event', ->
 
       it 'triggers the showSidebar() API', ->
         sandbox.spy host, "showSidebar"
-        publish  method: 'open'
+        publish 'open'
         assert.called host.showSidebar

h/static/scripts/widget-controller.coffee

@@ -51,15 +51,11 @@ module.exports = class WidgetController
         highlights = [annotation.$$tag]
       else
         highlights = []
-      crossframe.notify
-        method: 'focusAnnotations'
-        params: highlights
+      crossframe.call('focusAnnotations', highlights)
 
     $scope.scrollTo = (annotation) ->
       if angular.isObject annotation
-        crossframe.notify
-          method: 'scrollToAnnotation'
-          params: annotation.$$tag
+        crossframe.call('scrollToAnnotation', annotation.$$tag)
 
     $scope.shouldShowThread = (container) ->
       if annotationUI.hasSelectedAnnotations() and not container.parent.parent

package.json

@@ -25,6 +25,7 @@
     "dom-seek": "^1.0.1",
     "es6-promise": "^2.1.0",
     "extend": "^2.0.0",
+    "frame-rpc": "^1.3.1",
     "hammerjs": "^2.0.4",
     "jquery": "1.11.1",
     "jstimezonedetect": "1.0.5",
@@ -82,8 +83,7 @@
     "es6-promise": "./node_modules/es6-promise/dist/es6-promise.js",
     "hammerjs": "./node_modules/hammerjs/hammer.js",
     "jquery": "./node_modules/jquery/dist/jquery.js",
-    "jquery-scrollintoview": "./h/static/scripts/vendor/jquery.scrollintoview.js",
-    "jschannel": "./h/static/scripts/vendor/jschannel.js"
+    "jquery-scrollintoview": "./h/static/scripts/vendor/jquery.scrollintoview.js"
   },
   "browserify-shim": {
     "annotator": {
@@ -111,7 +111,6 @@
       "depends": [
         "jquery"
       ]
-    },
-    "jschannel": "Channel"
+    }
   }
 }