When the project's path changes, the TreeView's root directory updates.

spec/extensions/tree-view-spec.coffee

@@ -43,13 +43,27 @@ describe "TreeView", ->
       expect(rootEntries.find('> .file:contains(sample.js)')).toExist()
       expect(rootEntries.find('> .file:contains(sample.txt)')).toExist()
 
-    it "is empty when the project has not path", ->
-      treeView.deactivate()
+    describe "when the project has not path", ->
+      beforeEach ->
+        treeView.deactivate()
 
-      rootView = new RootView
-      rootView.activateExtension(TreeView)
-      treeView = rootView.find(".tree-view").view()
-      expect(treeView.root).not.toExist()
+        rootView = new RootView
+        rootView.activateExtension(TreeView)
+        treeView = rootView.find(".tree-view").view()
+
+      it "does not create a root node", ->
+        expect(treeView.root).not.toExist()
+
+      it "creates a root view when the project path is created", ->
+        rootView.open(require.resolve('fixtures/sample.js'))
+        expect(treeView.root.getPath()).toBe require.resolve('fixtures')
+        expect(treeView.root.parent()).toMatchSelector(".tree-view")
+
+        oldRoot = treeView.root
+
+        rootView.project.setPath('/tmp')
+        expect(treeView.root).not.toEqual oldRoot
+        expect(oldRoot.hasParent()).toBeFalsy()
 
   describe "serialization", ->
     newTreeView = null

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

@@ -51,6 +51,7 @@ class TreeView extends View
     @on 'tree-view:remove', => @removeSelectedEntry()
     @on 'tree-view:directory-modified', => @selectActiveFile()
     @rootView.on 'active-editor-path-change', => @selectActiveFile()
+    @rootView.project.on 'path-change', => @updateRoot()
 
     @on 'tree-view:unfocus', => @rootView.activeEditor()?.focus()
     @rootView.on 'tree-view:focus', => this.focus()
@@ -80,6 +81,11 @@ class TreeView extends View
 
     false
 
+  updateRoot: ->
+    @root?.remove()
+    @root = new DirectoryView(directory: @rootView.project.getRootDirectory(), isExpanded: true)
+    @append(@root)
+
   selectActiveFile: ->
     activeFilePath = @rootView.activeEditor()?.buffer.path
     @selectEntryForPath(activeFilePath)