Pressing left arrow on collapsed tree view root no longer raises an exception

spec/extensions/tree-view-spec.coffee

@@ -328,6 +328,13 @@ describe "TreeView", ->
           expect(subdir).toHaveClass 'selected'
           expect(treeView.root).toHaveClass 'expanded'
 
+      describe "when collapsed root directory is selected", ->
+        it "does not raise an error", ->
+          treeView.root.collapse()
+          treeView.selectEntry(treeView.root)
+
+          treeView.trigger 'tree-view:collapse-directory'
+
       describe "when a file is selected", ->
         it "collapses and selects the selected file's parent directory", ->
           subdir.find('.file').click()

src/extensions/tree-view/tree-view.coffee

@@ -120,9 +120,9 @@ class TreeView extends View
 
   collapseDirectory: ->
     selectedEntry = @selectedEntry()
-    directory = selectedEntry.closest('.expanded.directory').view()
-    directory.collapse()
-    @selectEntry(directory)
+    if directory = selectedEntry.closest('.expanded.directory').view()
+      directory.collapse()
+      @selectEntry(directory)
 
   openSelectedEntry: ->
     selectedEntry = @selectedEntry()