From d5fbe4b3b6d8458543ba1cfae3885b34a9677fb5 Mon Sep 17 00:00:00 2001
From: SteveSandersonMS <stevesa@microsoft.com>
Date: Fri, 11 Mar 2016 00:34:57 +0000
Subject: [PATCH] Fix aspnet-webpack package

---
 .../npm/aspnet-webpack/package.json           |  2 +-
 .../npm/aspnet-webpack/src/DeepClone.ts       |  3 ---
 .../npm/aspnet-webpack/src/LoadViaWebpack.ts  |  4 ++--
 .../npm/aspnet-webpack/src/RequireNewCopy.ts  | 22 +++++++++++++++++++
 .../src/WebpackDevMiddleware.ts               |  4 ++--
 5 files changed, 27 insertions(+), 8 deletions(-)
 delete mode 100644 src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/DeepClone.ts
 create mode 100644 src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/RequireNewCopy.ts

diff --git a/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/package.json b/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/package.json
index 8f1afee..ba04386 100644
--- a/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/package.json
+++ b/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/package.json
@@ -1,6 +1,6 @@
 {
   "name": "aspnet-webpack",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "Helpers for using Webpack in ASP.NET projects. Works in conjunction with the Microsoft.AspNet.SpaServices NuGet package.",
   "main": "index.js",
   "scripts": {
diff --git a/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/DeepClone.ts b/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/DeepClone.ts
deleted file mode 100644
index 102b658..0000000
--- a/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/DeepClone.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-export function deepClone<T>(serializableObject: T): T {
-    return JSON.parse(JSON.stringify(serializableObject));
-}
diff --git a/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/LoadViaWebpack.ts b/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/LoadViaWebpack.ts
index c11514f..50300d0 100644
--- a/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/LoadViaWebpack.ts
+++ b/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/LoadViaWebpack.ts
@@ -8,7 +8,7 @@ import ExternalsPlugin from 'webpack-externals-plugin';
 import requireFromString from 'require-from-string';
 import MemoryFS from 'memory-fs';
 import * as webpack from 'webpack';
-import { deepClone } from './DeepClone';
+import { requireNewCopy } from './RequireNewCopy';
 
 // Ensure we only go through the compile process once per [config, module] pair
 const loadViaWebpackPromisesCache: { [key: string]: any } = {};
@@ -32,7 +32,7 @@ export function loadViaWebpack<T>(webpackConfigPath: string, modulePath: string,
 function loadViaWebpackNoCache<T>(webpackConfigPath: string, modulePath: string) {
     return new Promise<T>((resolve, reject) => {
         // Load the Webpack config and make alterations needed for loading the output into Node
-        const webpackConfig: webpack.Configuration = deepClone(require(webpackConfigPath));
+        const webpackConfig: webpack.Configuration = requireNewCopy(webpackConfigPath);
         webpackConfig.entry = modulePath;
         webpackConfig.target = 'node';
         webpackConfig.output = { path: '/', filename: 'webpack-output.js', libraryTarget: 'commonjs' };
diff --git a/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/RequireNewCopy.ts b/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/RequireNewCopy.ts
new file mode 100644
index 0000000..940c83e
--- /dev/null
+++ b/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/RequireNewCopy.ts
@@ -0,0 +1,22 @@
+export function requireNewCopy(moduleNameOrPath: string): any {
+    // Store a reference to whatever's in the 'require' cache,
+    // so we don't permanently destroy it, and then ensure there's
+    // no cache entry for this module
+    const resolvedModule = require.resolve(moduleNameOrPath);
+    const wasCached = resolvedModule in require.cache;
+    let cachedInstance;
+    if (wasCached) {
+        cachedInstance = require.cache[resolvedModule];
+        delete require.cache[resolvedModule];
+    }
+
+    try {
+        // Return a new copy
+        return require(resolvedModule);
+    } finally {
+        // Restore the cached entry, if any
+        if (wasCached) {
+            require.cache[resolvedModule] = cachedInstance;
+        }
+    }
+}
diff --git a/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/WebpackDevMiddleware.ts b/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/WebpackDevMiddleware.ts
index 66f40c4..d15d861 100644
--- a/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/WebpackDevMiddleware.ts
+++ b/src/Microsoft.AspNet.SpaServices/npm/aspnet-webpack/src/WebpackDevMiddleware.ts
@@ -1,6 +1,6 @@
 import * as express from 'express';
 import * as webpack from 'webpack';
-import { deepClone } from './DeepClone';
+import { requireNewCopy } from './RequireNewCopy';
 
 export interface CreateDevServerCallback {
     (error: any, result: { Port: number, PublicPath: string }): void;
@@ -20,7 +20,7 @@ interface DevServerOptions {
 
 export function createWebpackDevServer(callback: CreateDevServerCallback, optionsJson: string) {
     const options: CreateDevServerOptions = JSON.parse(optionsJson);
-    const webpackConfig: webpack.Configuration = deepClone(require(options.webpackConfigPath));
+    const webpackConfig: webpack.Configuration = requireNewCopy(options.webpackConfigPath);
     const publicPath = (webpackConfig.output.publicPath || '').trim();
     if (!publicPath) {
         callback('To use the Webpack dev server, you must specify a value for \'publicPath\' on the \'output\' section of your webpack.config.', null);