AspNetCore + Angular 2: WebpackDevMiddleware Error with new project

Question

I'm creating a new project with this tutorial:

https://blogs.msdn.microsoft.com/webdev/2017/02/14/building-single-page-applications-on-asp-net-core-with-javascriptservices/

Next some resolved issues, I have now a complete project with all dependencies installed but when I launch the project with IIS, I have this error .

    L'exception System.AggregateException s'est produite
  HResult=0x80131500
  Message=One or more errors occurred.
  Source=<Impossible d'évaluer la source de l'exception>
  Arborescence des appels de procédure :
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at Microsoft.AspNetCore.Builder.WebpackDevMiddleware.UseWebpackDevMiddleware(IApplicationBuilder appBuilder, WebpackDevMiddlewareOptions options)
   at Test.Startup.Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory) in C:\VS2017\Project\Test\Startup.cs:line 44

Exception interne 1 :
Exception : Call to Node module failed with error: Webpack dev middleware failed because of an error while loading 'aspnet-webpack'. Error was: C:\VS2017\Project\Test\node_modules\webpack\lib\webpack.js:7
const Compiler = require("./Compiler");
^^^^^
SyntaxError: Use of const in strict mode.
    at exports.runInThisContext (vm.js:73:16)
    at Module._compile (module.js:443:25)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (C:\VS2017\Project\Test\node_modules\aspnet-webpack\WebpackDevMiddleware.js:4:15)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
Current directory is: C:\VS2017\Project\Test

I don't know wich step I failed so if someone already did it.

score 2 · Accepted Answer · edited Jun 20 '20 at 09:12

2

This happens because the aspnet-webpack node package requires a newer version of node.

The const and let are part of ECMAScript 2015 (a.k.a. ES6 and Harmony), and was not enabled by default in Node.js 0.10 or 0.12. Since Node.js 4.x, “All shipping [ES2015] features, which V8 considers stable, are turned on by default on Node.js and do NOT require any kind of runtime flag.”.

So by upgrading to Node.js 4.x or newer the error should disappear.

https://stackoverflow.com/a/23151062/5082427

Update

You can check the installed version of node by executing node -v in the command-line. If this command outputs an older version than the one you have installed, check the PATH environment variable to ensure you don't have multiple node installations.

edited Jun 20 '20 at 09:12

Community

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answered Apr 18 '17 at 12:55

Wazner

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Im using Node 6 – Elykx Apr 18 '17 at 12:56
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@Elykx are you sure? Could you type "node -v" in the command-line and comment the results? – Wazner Apr 18 '17 at 13:18
Thats what i get node -v v0.12.2 – Elykx Apr 18 '17 at 13:21
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So, you're not using Node 6. You're using Node 0.12.2. – Wazner Apr 18 '17 at 14:10
I installed this version https://nodejs.org/dist/v6.10.2/node-v6.10.2-x64.msi I don't know if i have to update something else – Elykx Apr 18 '17 at 14:12
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That's peculiar, it seems you have multiple versions of node installed then. Try checking your PATH environment variable and see if there are multiple paths to a node installation in there. – Wazner Apr 18 '17 at 14:18
Ah i had an other version installed on program files (x86), i removed it and its working now. Thanks for your time. – Elykx Apr 18 '17 at 14:28

AspNetCore + Angular 2: WebpackDevMiddleware Error with new project

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