more work on prefixReducer

Author: jedwards1211

README.md

@@ -59,3 +59,32 @@ Creates a middleware that delegates to a hot-swappable middleware.  The returned
 `replaceMiddleware(nextMiddleware: Middleware)` function.  This way you can use Webpack hot reloading on
 your custom middleware.
 
+## prefixReducer(prefix: string): (reducer: Reducer) => Reducer
+```js
+import {prefixReducer} from 'mindfront-redux-utils';
+```
+
+A reducer decorator that strips `prefix` from each `action.type` before passing it to the decorated `reducer`.
+If the `action.type` doesn't start with `prefix`, it will just return the `state` instead of calling `reducer`.
+
+If the decorated reducer has `actionHandlers` (from `createReducer`), then the returned reducer will have
+`actionHandlers` with the prefixed action type keys.
+
+### Example
+import {combineReducers} from 'redux'
+import {createReducer, prefixReducer} from 'mindfront-redux-utils'
+
+const counterReducer = createReducer(0, {
+  DECREMENT: state => state - 1,
+  INCREMENT: state => state + 1,
+})
+
+const reducer = combineReducers({
+  counter1: prefixReducer('COUNTER_1.')(counterReducer),
+  counter2: prefixReducer('COUNTER_2.')(counterReducer),
+})
+
+reducer({}, {type: 'COUNTER_1.INCREMENT'}) // {counter1: 1}
+reducer({counter1: 3, counter2: 3}, {type: 'COUNTER_1.DECREMENT'}) // {counter1: 2, counter2: 3}
+reducer({counter1: 3, counter2: 3}, {type: 'COUNTER_2.INCREMENT'}) // {counter1: 3, counter2: 4}
+

package.json

@@ -84,6 +84,7 @@
     "lodash.compact": "^3.0.1",
     "lodash.every": "^4.6.0",
     "lodash.foreach": "^4.5.0",
+    "lodash.mapkeys": "^4.6.0",
     "lodash.mapvalues": "^4.6.0",
     "lodash.memoize": "^4.1.2",
     "lodash.reduce": "^4.6.0",

src/prefixReducer.js

@@ -1,6 +1,14 @@
+import mapKeys from 'lodash.mapkeys'
+import createReducer from './createReducer'
+
 export default function prefixReducerActionTypes(prefix) {
-  return reducer => (state, action) => action.type.startsWith(prefix)
-    ? reducer(state, {...action, type: action.type.substring(prefix.length)})
-    : state
+  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)
+      ? reducer(state, {...action, type: action.type.substring(prefix.length)})
+      : state
+  }
 }
 

test/prefixReducer.js

@@ -1,14 +1,30 @@
 import {expect} from 'chai'
+import createReducer from '../src/createReducer'
 import prefixReducer from '../src/prefixReducer'
 
 describe('prefixReducer', () => {
-  const reducer = (state, action) => action.type === 'INCREMENT' ? state + 1 : state
-
-  it('works', () => {
+  it('works for basic reducer', () => {
+    const reducer = (state, action) => action.type === 'INCREMENT' ? state + 1 : state
+    const reducer2 = prefixReducer('TEST.')(reducer)
+    expect(reducer2(1, {type: 'INCREMENT'})).to.equal(1)
+    expect(reducer2(1, {type: 'TEST.INCREMENT'})).to.equal(2)
+    expect(reducer2(1, {type: 'BLAH.INCREMENT'})).to.equal(1)
+  })
+  it('works for action map reducer', () => {
+    const reducer = createReducer(0, {
+      INCREMENT: state => state + 1,
+      DECREMENT: state => state - 1,
+    })
     const reducer2 = prefixReducer('TEST.')(reducer)
+    expect(reducer2.initialState).to.equal(0)
+    expect(reducer2.actionHandlers['TEST.INCREMENT']).to.be.an.instanceof(Function)
+    expect(reducer2.actionHandlers['TEST.DECREMENT']).to.be.an.instanceof(Function)
     expect(reducer2(1, {type: 'INCREMENT'})).to.equal(1)
     expect(reducer2(1, {type: 'TEST.INCREMENT'})).to.equal(2)
     expect(reducer2(1, {type: 'BLAH.INCREMENT'})).to.equal(1)
+    expect(reducer2(1, {type: 'DECREMENT'})).to.equal(1)
+    expect(reducer2(1, {type: 'TEST.DECREMENT'})).to.equal(0)
+    expect(reducer2(1, {type: 'BLAH.DECREMENT'})).to.equal(1)
   })
 })