Accept documents in EditSession and replicate scroll position

spec/app/edit-session-replication-spec.coffee

@@ -0,0 +1,26 @@
+{createSite} = require 'telepath'
+Editor = require 'editor'
+
+describe "EditSession replication", ->
+  [editSession1, editSession2] = []
+  beforeEach ->
+    editSession1 = project.open('sample.js')
+    doc1 = editSession1.getState()
+    doc2 = doc1.clone(createSite(2))
+    doc1.connect(doc2)
+    editSession2 = deserialize(doc2)
+
+  it "replicates the scroll position", ->
+    editor1 = new Editor(editSession1)
+    editor2 = new Editor(editSession2)
+
+    editor1.attachToDom().width(50).height(50)
+    editor2.attachToDom().width(50).height(50)
+
+    editor1.scrollTop(10)
+    expect(editor1.scrollTop()).toBe 10
+    expect(editor2.scrollTop()).toBe 10
+
+    editor2.scrollLeft(20)
+    expect(editor2.scrollLeft()).toBe 20
+    expect(editor1.scrollLeft()).toBe 20