From 9345fc6f775154e597b77d1339e962c79cd5b41a Mon Sep 17 00:00:00 2001
From: Andrew Duthie <andrew@andrewduthie.com>
Date: Thu, 8 Jun 2017 16:42:57 -0400
Subject: [PATCH] Test history when deciding to return same state

---
 editor/utils/test/undoable-reducer.js | 14 +++++++++++---
 editor/utils/undoable-reducer.js      |  2 +-
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/editor/utils/test/undoable-reducer.js b/editor/utils/test/undoable-reducer.js
index 44d5e75299877a..1c7a020651d0a2 100644
--- a/editor/utils/test/undoable-reducer.js
+++ b/editor/utils/test/undoable-reducer.js
@@ -84,10 +84,11 @@ describe( 'undoableReducer', () => {
 	} );
 
 	describe( 'combineUndoableReducers()', () => {
+		const reducer = combineUndoableReducers( {
+			count: ( state = 0 ) => state,
+		} );
+
 		it( 'should return a combined reducer with getters', () => {
-			const reducer = combineUndoableReducers( {
-				count: ( state = 0 ) => state,
-			} );
 			const state = reducer( undefined, {} );
 
 			expect( typeof reducer ).toBe( 'function' );
@@ -100,5 +101,12 @@ describe( 'undoableReducer', () => {
 				future: [],
 			} );
 		} );
+
+		it( 'should return same reference if state has not changed', () => {
+			const original = reducer( undefined, {} );
+			const state = reducer( original, {} );
+
+			expect( state ).toBe( original );
+		} );
 	} );
 } );
diff --git a/editor/utils/undoable-reducer.js b/editor/utils/undoable-reducer.js
index d254bcea3721f4..95415ff02828ce 100644
--- a/editor/utils/undoable-reducer.js
+++ b/editor/utils/undoable-reducer.js
@@ -96,7 +96,7 @@ export function combineUndoableReducers( reducers, options ) {
 
 	return ( state = initialState, action ) => {
 		const nextState = reducer( state.history, action );
-		if ( nextState === state.history.present ) {
+		if ( nextState === state.history ) {
 			return state;
 		}