Stub out the tests for CrossFrameDiscovery

tests/js/cross-frame-discovery-test.coffee

+assert = chai.assert
+sinon.assert.expose assert, prefix: null
+
+describe 'CrossFrameDiscovery', ->
+  sandbox = sinon.sandbox.create()
+  fakeWindow = null
+  createDiscovery = null
+
+  beforeEach module('h')
+  beforeEach inject (CrossFrameDiscovery) ->
+    fakeWindow = {
+      top: null
+      addEventListener: sandbox.stub()
+      removeEventListener: sandbox.stub()
+    }
+    createBridge = (options) ->
+      new CrossFrameDiscovery(fakeWindow, options)
+
+  afterEach ->
+    sandbox.restore()
+
+  describe 'startDiscovery', ->
+    it 'adds a "message" listener to the window object'
+
+    describe 'when acting as a server (options.server = true)', ->
+      it 'sends out a "discovery" message to every frame'
+      it 'does not send the message to itself'
+      it 'sends an "ack" on receiving a "request"'
+      it 'calls the discovery callback on receiving "request"'
+
+    describe 'when acting as a client (options.client = false)', ->
+      it 'sends out a discovery message to every frame'
+      it 'does not send the message to itself'
+      it 'sends a "request" in response to an "offer"'
+      it 'does not respond to an "offer" if a "request" is already in progress'
+      it 'allows responding to a "request" once a previous "request" has completed'
+      it 'calls the discovery callback on receiving an "ack"'
+
+  describe 'stopDiscovery', ->
+    it 'removes the "message" listener from the window'
+    it 'allows startDiscovery to be called with a new handler'