Mock out document.title with Object.defineProperty

Previously the WorkspaceView::setTitle was mocked in specs to prevent
the title from changing. But I would like to move the title update logic
without breaking assertions, so now we can assert directly on
document.title.

spec/spec-helper.coffee

@@ -35,6 +35,12 @@ $(window).on 'beforeunload', ->
   atom.saveSync()
 $('html,body').css('overflow', 'auto')
 
+# Allow document.title to be assigned in specs without screwing up spec window title
+documentTitle = null
+Object.defineProperty document, 'title',
+  get: -> documentTitle
+  set: (title) -> documentTitle = title
+
 jasmine.getEnv().addEqualityTester(_.isEqual) # Use underscore's definition of equality for toEqual assertions
 
 if process.platform is 'win32' and process.env.JANKY_SHA1
@@ -61,6 +67,7 @@ isCoreSpec = specDirectory == fs.realpathSync(__dirname)
 beforeEach ->
   Grim.clearDeprecations() if isCoreSpec
   $.fx.off = true
+  documentTitle = null
   projectPath = specProjectPath ? path.join(@specDirectory, 'fixtures')
   atom.project = new Project(path: projectPath)
   atom.workspace = new Workspace()
@@ -106,7 +113,7 @@ beforeEach ->
   spyOn(EditorView.prototype, 'requestDisplayUpdate').andCallFake -> @updateDisplay()
   EditorComponent.performSyncUpdates = true
 
-  spyOn(WorkspaceView.prototype, 'setTitle').andCallFake (@title) ->
+  spyOn(atom, "setRepresentedFilename")
   spyOn(window, "setTimeout").andCallFake window.fakeSetTimeout
   spyOn(window, "clearTimeout").andCallFake window.fakeClearTimeout
   spyOn(pathwatcher.File.prototype, "detectResurrectionAfterDelay").andCallFake -> @detectResurrection()

spec/workspace-view-spec.coffee

@@ -49,7 +49,7 @@ describe "WorkspaceView", ->
 
           expect(atom.workspaceView.getEditorViews().length).toBe 2
           expect(atom.workspaceView.getActivePaneView()).toBe atom.workspaceView.getPaneViews()[1]
-          expect(atom.workspaceView.title).toBe "untitled - #{atom.project.getPath()}"
+          expect(document.title).toBe "untitled - #{atom.project.getPath()}"
 
     describe "when there are open editors", ->
       it "constructs the view with the same panes", ->
@@ -106,7 +106,7 @@ describe "WorkspaceView", ->
           expect(editorView3).not.toHaveFocus()
           expect(editorView4).not.toHaveFocus()
 
-          expect(atom.workspaceView.title).toBe "#{path.basename(editorView2.getEditor().getPath())} - #{atom.project.getPath()}"
+          expect(document.title).toBe "#{path.basename(editorView2.getEditor().getPath())} - #{atom.project.getPath()}"
 
     describe "where there are no open editors", ->
       it "constructs the view with no open editors", ->
@@ -145,7 +145,7 @@ describe "WorkspaceView", ->
     describe "when the project has no path", ->
       it "sets the title to 'untitled'", ->
         atom.project.setPath(undefined)
-        expect(atom.workspaceView.title).toBe 'untitled'
+        expect(document.title).toBe 'untitled'
 
     describe "when the project has a path", ->
       beforeEach ->
@@ -155,40 +155,40 @@ describe "WorkspaceView", ->
       describe "when there is an active pane item", ->
         it "sets the title to the pane item's title plus the project path", ->
           item = atom.workspace.getActivePaneItem()
-          expect(atom.workspaceView.title).toBe "#{item.getTitle()} - #{atom.project.getPath()}"
+          expect(document.title).toBe "#{item.getTitle()} - #{atom.project.getPath()}"
 
       describe "when the title of the active pane item changes", ->
         it "updates the window title based on the item's new title", ->
           editor = atom.workspace.getActivePaneItem()
           editor.buffer.setPath(path.join(temp.dir, 'hi'))
-          expect(atom.workspaceView.title).toBe "#{editor.getTitle()} - #{atom.project.getPath()}"
+          expect(document.title).toBe "#{editor.getTitle()} - #{atom.project.getPath()}"
 
       describe "when the active pane's item changes", ->
         it "updates the title to the new item's title plus the project path", ->
           atom.workspaceView.getActivePaneView().activateNextItem()
           item = atom.workspace.getActivePaneItem()
-          expect(atom.workspaceView.title).toBe "#{item.getTitle()} - #{atom.project.getPath()}"
+          expect(document.title).toBe "#{item.getTitle()} - #{atom.project.getPath()}"
 
       describe "when the last pane item is removed", ->
         it "updates the title to contain the project's path", ->
           atom.workspaceView.getActivePaneView().remove()
           expect(atom.workspace.getActivePaneItem()).toBeUndefined()
-          expect(atom.workspaceView.title).toBe atom.project.getPath()
+          expect(document.title).toBe atom.project.getPath()
 
       describe "when an inactive pane's item changes", ->
         it "does not update the title", ->
           pane = atom.workspaceView.getActivePaneView()
           pane.splitRight()
-          initialTitle = atom.workspaceView.title
+          initialTitle = document.title
           pane.activateNextItem()
-          expect(atom.workspaceView.title).toBe initialTitle
+          expect(document.title).toBe initialTitle
 
     describe "when the root view is deserialized", ->
       it "updates the title to contain the project's path", ->
         workspace2 = atom.workspace.testSerialization()
         workspaceView2 = workspace2.getView(workspace2).__spacePenView
         item = atom.workspace.getActivePaneItem()
-        expect(workspaceView2.title).toBe "#{item.getTitle()} - #{atom.project.getPath()}"
+        expect(document.title).toBe "#{item.getTitle()} - #{atom.project.getPath()}"
         workspaceView2.remove()
 
   describe "window:toggle-invisibles event", ->