Throw an error if peer dependency is not installed

README.md

@@ -4,7 +4,7 @@
 
 ### What is react-engine?
 * a react render engine for [Universal](https://medium.com/@mjackson/universal-javascript-4761051b7ae9) (previously [Isomorphic](http://nerds.airbnb.com/isomorphic-javascript-future-web-apps/)) JavaScript apps written with express
-* renders both plain react views and react-router views
+* renders both plain react views and **optionally** react-router views
 * enables server rendered views to be client mountable
 
 

lib/client.js

@@ -15,9 +15,7 @@
 
 'use strict';
 
-var React = require('react');
 var Config = require('./config');
-var Router = require('react-router');
 
 // declaring like this helps in unit test
 // dependency injection using `rewire` module
@@ -37,6 +35,16 @@ exports.data = function data() {
 // the client side boot function
 exports.boot = function boot(options, callback) {
 
+  var React = require('react');
+
+  try {
+    var Router = require('react-router');
+  } catch (err) {
+    if (!Router && createOptions.routes) {
+      throw err;
+    }
+  }
+
   var router;
 
   var viewResolver = options.viewResolver;

lib/server.js

@@ -25,10 +25,6 @@ var omit = require('lodash-node/compat/object/omit');
 var merge = require('lodash-node/compat/object/merge');
 var isString = require('lodash-node/compat/lang/isString');
 
-// safely require the peer-dependencies
-var React = util.safeRequire('react');
-var Router = util.safeRequire('react-router');
-
 // a template of the `script` tag that gets
 // injected into the server rendered pages.
 var TEMPLATE = ['<script id="%s" type="application/javascript">var ',
@@ -38,6 +34,17 @@ var TEMPLATE = ['<script id="%s" type="application/javascript">var ',
 
 exports.create = function create(createOptions) {
 
+  // safely require the peer-dependencies
+  var React = util.safeRequire('react');
+
+  try {
+    var Router = require('react-router');
+  } catch (err) {
+    if (!Router && createOptions.routes) {
+      throw err;
+    }
+  }
+
   createOptions = createOptions || {};
   createOptions.docType = isString(createOptions.docType) ? createOptions.docType : Config.docType;
   createOptions.renderOptionsKeysToFilter = createOptions.renderOptionsKeysToFilter || [];