Split out route replacement logic into its own module

Author: acdlite

src/__tests__/reduxReactRouter-test.js

@@ -95,10 +95,8 @@ describe('reduxRouter()', () => {
       router: routerStateReducer
     });
 
-    const history = createHistory();
-
     const store = reduxReactRouter({
-      history,
+      createHistory,
       routes
     })(createStore)(reducer);
 

src/client.js

@@ -2,7 +2,8 @@ import { compose } from 'redux';
 import { routerDidChange } from './actionCreators';
 import routerStateEquals from './routerStateEquals';
 import reduxReactRouter from './reduxReactRouter';
-import transformOptions from './transformOptions';
+import useDefaults from './useDefaults';
+import routeReplacement from './routeReplacement';
 
 function client(next) {
   return options => createStore => (reducer, initialState) => {
@@ -44,6 +45,7 @@ function client(next) {
 }
 
 export default compose(
-  transformOptions,
+  useDefaults,
+  routeReplacement,
   client
 )(reduxReactRouter);

src/transformOptions.js renamed to src/routeReplacement.js

@@ -2,26 +2,15 @@ import { applyMiddleware, compose } from 'redux';
 import { createRoutes } from 'react-router';
 import replaceRoutesMiddleware from './replaceRoutesMiddleware';
 
-const defaults = {
-  onError: error => { throw error; },
-  routerStateSelector: state => state.router
-};
-
-export default function transformOptions(next) {
+export default function routeReplacement(next) {
   return options => createStore => (reducer, initialState) => {
     const {
       routes: baseRoutes,
-      createHistory: baseCreateHistory,
-      history: baseHistory,
       routerStateSelector
-    } = { ...defaults, ...options };
+    } = options;
 
     let store;
 
-    const createHistory = !baseCreateHistory && baseHistory
-      ? () => baseHistory
-      : null;
-
     let childRoutes = [];
     let areChildRoutesResolved = false;
     const childRoutesCallbacks = [];
@@ -59,10 +48,8 @@ export default function transformOptions(next) {
         replaceRoutesMiddleware(replaceRoutes)
       ),
       next({
-        ...defaults,
         ...options,
-        routes: createRoutes(routes),
-        createHistory
+        routes: createRoutes(routes)
       })
     )(createStore)(reducer, initialState);
 

src/server.js

@@ -1,7 +1,8 @@
 import { compose, applyMiddleware } from 'redux';
 import createMemoryHistory from 'history/lib/createMemoryHistory';
 import baseReduxReactRouter from './reduxReactRouter';
-import transformOptions from './transformOptions';
+import useDefaults from './useDefaults';
+import routeReplacement from './routeReplacement';
 import matchMiddleware from './matchMiddleware';
 import { MATCH } from './constants';
 
@@ -31,6 +32,7 @@ export function match(url, callback) {
 }
 
 export const reduxReactRouter = compose(
-  transformOptions,
+  useDefaults,
+  routeReplacement,
   server
 )(baseReduxReactRouter);

src/useDefaults.js

@@ -0,0 +1,29 @@
+const defaults = {
+  onError: error => { throw error; },
+  routerStateSelector: state => state.router
+};
+
+export default function useDefaults(next) {
+  return options => createStore => (reducer, initialState) => {
+    const optionsWithDefaults = { ...defaults, ...options };
+
+    const {
+      createHistory: baseCreateHistory,
+      history: baseHistory,
+    } = optionsWithDefaults;
+
+    let createHistory;
+    if (typeof baseCreateHistory === 'function') {
+      createHistory = baseCreateHistory;
+    } else if (baseHistory) {
+      createHistory = () => baseHistory;
+    } else {
+      createHistory = null;
+    }
+
+    return next({
+      ...optionsWithDefaults,
+      createHistory
+    })(createStore)(reducer, initialState);
+  };
+}