Restore entries attribute in MemoryHistory interface

packages/history/__tests__/memory-test.js

@@ -27,6 +27,10 @@ describe("a memory history", () => {
     expect(typeof history.index).toBe("number");
   });
 
+  it('has an entries property', () => {
+    expect(Array.isArray(history.entries)).toBe(true);
+  });
+
   it("knows how to create hrefs", () => {
     const href = history.createHref({
       pathname: "/the/path",

packages/history/index.ts

@@ -315,6 +315,7 @@ export interface HashHistory extends History {}
  */
 export interface MemoryHistory extends History {
   readonly index: number;
+  readonly entries: Location[];
 }
 
 const readOnly: <T>(obj: T) => Readonly<T> = __DEV__
@@ -973,6 +974,9 @@ export function createMemoryHistory(
     get index() {
       return index;
     },
+    get entries() {
+      return entries;
+    },
     get action() {
       return action;
     },