Add Node project path to webpack middleware options

Author: Matt Cole

src/Microsoft.AspNetCore.SpaServices/Webpack/WebpackDevMiddleware.cs

@@ -41,9 +41,10 @@ public static void UseWebpackDevMiddleware(
             // middleware). And since this is a dev-time-only feature, it doesn't matter if the default transport isn't
             // as fast as some theoretical future alternative.
             var hostEnv = (IHostingEnvironment)appBuilder.ApplicationServices.GetService(typeof(IHostingEnvironment));
+            var projectPath = options.ProjectPath ?? hostEnv.ContentRootPath;
             var nodeServices = Configuration.CreateNodeServices(new NodeServicesOptions
             {
-                ProjectPath = hostEnv.ContentRootPath,
+                ProjectPath = projectPath,
                 WatchFileExtensions = new string[] { } // Don't watch anything
             });
 
@@ -55,7 +56,7 @@ public static void UseWebpackDevMiddleware(
             // Tell Node to start the server hosting webpack-dev-middleware
             var devServerOptions = new
             {
-                webpackConfigPath = Path.Combine(hostEnv.ContentRootPath, options.ConfigFile ?? DefaultConfigFile),
+                webpackConfigPath = Path.Combine(projectPath, options.ConfigFile ?? DefaultConfigFile),
                 suppliedOptions = options
             };
             var devServerInfo =

src/Microsoft.AspNetCore.SpaServices/Webpack/WebpackDevMiddlewareOptions.cs

@@ -6,5 +6,6 @@ public class WebpackDevMiddlewareOptions
         public int HotModuleReplacementServerPort { get; set; }
         public bool ReactHotModuleReplacement { get; set; }
         public string ConfigFile { get; set; }
+        public string ProjectPath { get; set; }
     }
 }