When a new edit session is added, add a new tab for it

src/extensions/tabs/spec/tabs-spec.coffee

@@ -46,3 +46,9 @@ describe "Tabs", ->
       editor.setActiveEditSessionIndex(1)
       expect(tabs.find('.active').length).toBe 1
       expect(tabs.find('.tab:eq(1)')).toHaveClass 'active'
+
+  describe "when a new edit session is created", ->
+    it "adds a tab for the new edit session", ->
+      rootView.open('two-hundred.txt')
+      expect(tabs.find('.tab').length).toBe 3
+      expect(tabs.find('.tab:eq(2) .file-name').text()).toBe 'two-hundred.txt'

src/extensions/tabs/src/tabs.coffee

@@ -20,13 +20,18 @@ class Tabs extends View
 
   initialize: (@editor) ->
     for editSession, index in @editor.editSessions
-      @append $$ ->
-        @div class: 'tab', =>
-          @div editSession.buffer.getBaseName(), class: 'file-name'
+      @addTabForEditSession(editSession)
 
     @setActiveTab(@editor.getActiveEditSessionIndex())
     @editor.on 'editor:active-edit-session-changed', (e, index) => @setActiveTab(index)
 
+    @editor.on 'editor:edit-session-added', (e, editSession) => @addTabForEditSession(editSession)
+
+  addTabForEditSession: (editSession) ->
+    @append $$ ->
+      @div class: 'tab', =>
+        @div editSession.buffer.getBaseName(), class: 'file-name'
+
   setActiveTab: (index) ->
     @find(".tab.active").removeClass('active')
     @find(".tab:eq(#{index})").addClass('active')