fix(prefixReducer): ignore non-string action.type

Author: jedwards1211

src/prefixReducer.js

@@ -1,12 +1,12 @@
 import mapKeys from 'lodash.mapkeys'
 import createReducer from './createReducer'
 
-export default function prefixReducerActionTypes(prefix) {
+export default function prefixReducer(prefix) {
   return reducer => {
     if (reducer.actionHandlers instanceof Object) {
       return createReducer(reducer.initialState, mapKeys(reducer.actionHandlers, (handler, key) => prefix + key))
     }
-    return (state, action) => action.type.startsWith(prefix)
+    return (state, action) => typeof action.type === 'string' && action.type.startsWith(prefix)
       ? reducer(state, {...action, type: action.type.substring(prefix.length)})
       : state
   }

test/prefixReducerTest.js

@@ -26,6 +26,16 @@ describe('prefixReducer', () => {
     expect(reducer2(1, {type: 'TEST.DECREMENT'})).to.equal(0)
     expect(reducer2(1, {type: 'BLAH.DECREMENT'})).to.equal(1)
   })
+  it('ignores actions without type', () => {
+    const reducer = (state, action) => action.type === 'INCREMENT' ? state + 1 : state
+    const reducer2 = prefixReducer('TEST.')(reducer)
+    expect(reducer2(1, {})).to.equal(1)
+  })
+  it('ignores actions non-string type', () => {
+    const reducer = (state, action) => action.type === 'INCREMENT' ? state + 1 : state
+    const reducer2 = prefixReducer('TEST.')(reducer)
+    expect(reducer2(1, {type: {}})).to.equal(1)
+  })
 })