diff --git a/spec/workspace-spec.coffee b/spec/workspace-spec.coffee
index e6f75e15c..ade8664b6 100644
--- a/spec/workspace-spec.coffee
+++ b/spec/workspace-spec.coffee
@@ -65,3 +65,58 @@ describe "Workspace", ->
         expect(workspace.paneContainer.root.children).toEqual [pane1, pane2]
         expect(pane1.items.length).toBe 0
         expect(pane2.items.length).toBe 2
+
+  describe "::openSingletonSync(uri, options)", ->
+    describe "when an editor for the given uri is already open on the active pane", ->
+      it "activates the existing editor", ->
+        editor1 = workspace.openSync('a')
+        editor2 = workspace.openSync('b')
+        expect(workspace.activePaneItem).toBe editor2
+        workspace.openSingletonSync('a')
+        expect(workspace.activePaneItem).toBe editor1
+
+    describe "when an editor for the given uri is already open on an inactive pane", ->
+      it "activates the existing editor on the inactive pane, then activates that pane", ->
+        editor1 = workspace.openSync('a')
+        pane1 = workspace.activePane
+        pane2 = workspace.activePane.splitRight()
+        editor2 = workspace.openSync('b')
+        expect(workspace.activePaneItem).toBe editor2
+        workspace.openSingletonSync('a')
+        expect(workspace.activePane).toBe pane1
+        expect(workspace.activePaneItem).toBe editor1
+
+    describe "when no editor for the given uri is open in any pane", ->
+      it "opens an editor for the given uri in the active pane", ->
+        editor1 = workspace.openSingletonSync('a')
+        expect(workspace.activePaneItem).toBe editor1
+
+      describe "when the 'split' option is 'left'", ->
+        it "opens the editor in the leftmost pane of the current pane axis", ->
+          pane1 = workspace.activePane
+          pane2 = pane1.splitRight()
+          expect(workspace.activePane).toBe pane2
+          editor1 = workspace.openSingletonSync('a', split: 'left')
+          expect(workspace.activePane).toBe pane1
+          expect(pane1.items).toEqual [editor1]
+          expect(pane2.items).toEqual []
+
+      describe "when the 'split' option is 'right'", ->
+        describe "when the active pane is in a horizontal pane axis", ->
+          it "activates the editor on the rightmost pane of the current pane axis", ->
+            pane1 = workspace.activePane
+            pane2 = pane1.splitRight()
+            pane1.activate()
+            editor1 = workspace.openSingletonSync('a', split: 'right')
+            expect(workspace.activePane).toBe pane2
+            expect(pane2.items).toEqual [editor1]
+            expect(pane1.items).toEqual []
+
+        describe "when the active pane is not in a horizontal pane axis", ->
+          it "splits the current pane to the right, then activates the editor on the right pane", ->
+            pane1 = workspace.activePane
+            editor1 = workspace.openSingletonSync('a', split: 'right')
+            pane2 = workspace.activePane
+            expect(workspace.paneContainer.root.children).toEqual [pane1, pane2]
+            expect(pane2.items).toEqual [editor1]
+            expect(pane1.items).toEqual []
diff --git a/spec/workspace-view-spec.coffee b/spec/workspace-view-spec.coffee
index 30ea866b5..00ab624aa 100644
--- a/spec/workspace-view-spec.coffee
+++ b/spec/workspace-view-spec.coffee
@@ -185,56 +185,6 @@ describe "WorkspaceView", ->
       atom.workspaceView.trigger 'window:decrease-font-size'
       expect(atom.config.get('editor.fontSize')).toBe 1
 
-  describe ".openSingletonSync(filePath, options)", ->
-    [pane1] = []
-    beforeEach ->
-      pane1 = atom.workspaceView.getActivePane()
-
-    it "creates a new pane and reuses the file when already open", ->
-      atom.workspaceView.openSingletonSync('b', split: 'right')
-      pane2 = atom.workspaceView.getActivePane()
-      expect(pane2[0]).not.toBe pane1[0]
-      expect(pane1.itemForUri('b')).toBeFalsy()
-      expect(pane2.itemForUri('b')).not.toBeFalsy()
-      expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
-
-      pane1.activate()
-      expect(atom.workspaceView.getActivePane()[0]).toBe pane1[0]
-
-      atom.workspaceView.openSingletonSync('b', split: 'right')
-      pane3 = atom.workspaceView.getActivePane()
-      expect(pane3[0]).toBe pane2[0]
-      expect(pane1.itemForUri('b')).toBeFalsy()
-      expect(pane2.itemForUri('b')).not.toBeFalsy()
-      expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
-
-    it "handles split: left by opening to the left pane when necessary", ->
-      atom.workspaceView.openSingletonSync('b', split: 'right')
-      pane2 = atom.workspaceView.getActivePane()
-      expect(pane2[0]).not.toBe pane1[0]
-
-      atom.workspaceView.openSingletonSync('file1', split: 'left')
-
-      activePane = atom.workspaceView.getActivePane()
-      expect(activePane[0]).toBe pane1[0]
-
-      expect(pane1.itemForUri('file1')).toBeTruthy()
-      expect(pane2.itemForUri('file1')).toBeFalsy()
-      expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
-
-      pane2.activate()
-      expect(atom.workspaceView.getActivePane()[0]).toBe pane2[0]
-
-      atom.workspaceView.openSingletonSync('file1', split: 'left')
-      activePane = atom.workspaceView.getActivePane()
-      expect(activePane[0]).toBe pane1[0]
-      expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
-
-    it "reuses the file when already open", ->
-      atom.workspaceView.openSync('b')
-      atom.workspaceView.openSingletonSync('b', split: 'right')
-      expect(atom.workspaceView.panes.find('.pane').toArray()).toEqual [pane1[0]]
-
   describe ".open(filePath)", ->
     [activePane] = []