Fix for prerendering hanging if webpack compilation fails

Author: SteveSandersonMS

src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/package.json

@@ -1,6 +1,6 @@
 {
   "name": "aspnet-webpack",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "Helpers for using Webpack in ASP.NET Core projects. Works in conjunction with the Microsoft.AspNetCore.SpaServices NuGet package.",
   "main": "index.js",
   "scripts": {

src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/src/LoadViaWebpack.ts

@@ -52,7 +52,7 @@ function loadViaWebpackNoCache<T>(webpackConfigPath: string, modulePath: string)
         webpackConfig.plugins = webpackConfig.plugins.filter(plugin => {
             return !(plugin instanceof webpack.optimize.CommonsChunkPlugin);
         });
-        
+
         // The typical use case for DllReferencePlugin is for referencing vendor modules. In a Node
         // environment, it doesn't make sense to load them from a DLL bundle, nor would that even
         // work, because then you'd get different module instances depending on whether a module
@@ -78,9 +78,14 @@ function loadViaWebpackNoCache<T>(webpackConfigPath: string, modulePath: string)
             if (err) {
                 reject(err);
             } else {
-                const fileContent = compiler.outputFileSystem.readFileSync('/webpack-output.js', 'utf8');
-                const moduleInstance = requireFromString<T>(fileContent);
-                resolve(moduleInstance);
+                // We're in a callback, so need an explicit try/catch to propagate any errors up the promise chain
+                try {
+                    const fileContent = compiler.outputFileSystem.readFileSync('/webpack-output.js', 'utf8');
+                    const moduleInstance = requireFromString<T>(fileContent);
+                    resolve(moduleInstance);
+                } catch(ex) {
+                    reject(ex);
+                }
             }
         });
     });