Put a key on memory history's initial location

modules/__tests__/MemoryHistory-test.js

@@ -15,8 +15,8 @@ describe('a memory history', () => {
     })
 
     describe('the initial location', () => {
-      it('does not have a key', (done) => {
-        TestSequences.InitialLocationNoKey(history, done)
+      it('has a key', (done) => {
+        TestSequences.InitialLocationHasKey(history, done)
       })
     })
 

modules/__tests__/TestSequences/InitialLocationHasKey.js

@@ -0,0 +1,12 @@
+import expect from 'expect'
+import execSteps from './execSteps'
+
+export default (history, done) => {
+  const steps = [
+    (location) => {
+      expect(location.key).toExist()
+    }
+  ]
+
+  execSteps(steps, history, done)
+}

modules/__tests__/TestSequences/index.js

@@ -9,6 +9,7 @@ export GoForward from './GoForward'
 export HashbangHashPathCoding from './HashbangHashPathCoding'
 export HashChangeTransitionHook from './HashChangeTransitionHook'
 export InitialLocationNoKey from './InitialLocationNoKey'
+export InitialLocationHasKey from './InitialLocationHasKey'
 export Listen from './Listen'
 export NoslashHashPathCoding from './NoslashHashPathCoding'
 export PushNewLocation from './PushNewLocation'

modules/createMemoryHistory.js

@@ -34,10 +34,10 @@ const createMemoryHistory = (props = {}) => {
     Math.random().toString(36).substr(2, keyLength)
 
   const index = clamp(initialIndex, 0, initialEntries.length - 1)
-  const entries = initialEntries.map((entry, index) => (
+  const entries = initialEntries.map(entry => (
     typeof entry === 'string'
-      ? createLocation(entry, undefined, index ? createKey() : undefined)
-      : createLocation(entry, undefined, index ? (entry.key || createKey()) : undefined)
+      ? createLocation(entry, undefined, createKey())
+      : createLocation(entry, undefined, entry.key || createKey())
   ))
 
   // Public interface