fix: use better cloning method to preserve regexes

Author: chrisbreiding

index.js

@@ -1,3 +1,4 @@
+const cloneDeep = require('lodash.clonedeep')
 const path = require('path')
 const webpack = require('webpack')
 const log = require('debug')('cypress:webpack')
@@ -167,6 +168,6 @@ const preprocessor = (options = {}) => {
 }
 
 // provide a clone of the default options
-preprocessor.defaultOptions = JSON.parse(JSON.stringify(defaultOptions))
+preprocessor.defaultOptions = cloneDeep(defaultOptions)
 
 module.exports = preprocessor

package.json

@@ -64,6 +64,7 @@
     "babel-preset-react": "6.24.1",
     "bluebird": "3.5.0",
     "debug": "3.1.0",
+    "lodash.clonedeep": "4.5.0",
     "webpack": "3.6.0"
   },
   "release": {

test/index_spec.js

@@ -64,6 +64,10 @@ describe('webpack preprocessor', function () {
       expect(preprocessor.defaultOptions).to.be.an('object')
       expect(preprocessor.defaultOptions.webpackOptions.module.rules).to.be.an('array')
     })
+
+    it('defaultOptions are deeply cloned, preserving regexes', () => {
+      expect(preprocessor.defaultOptions.webpackOptions.module.rules[0].test).to.be.an.instanceOf(RegExp)
+    })
   })
 
   describe('preprocessor function', function () {