serve crashes on websocket close

[epelc]

Bug Report or Feature Request (mark with an x)

- [x] bug report -> please search issues before submitting
- [ ] feature request

Area

- [x] devkit
- [ ] schematics

Versions

npm 6.1.0

Angular CLI: 6.0.7
Node: 10.3.0
OS: darwin x64
Angular: 6.0.3

Repro steps

Run the cli serve command with proxying to a backend websocket server(turn "ws":true on for one of your endpoints) and return an error from the websocket server. The cli proxy server will crash with the error below.

Specifically if you return an http error status code before the websocket request is upgraded to the websocket protocol. Here is the server returning the error code(it's in golang) but you can roughly see that in this example the error returned is well before the protocol change so it is just a regular http 403 error.

The log given by the failure

ℹ ｢wdm｣: Compiled successfully.
events.js:167
      throw er; // Unhandled 'error' event
      ^

Error: read ECONNRESET
    at TCP.onread (net.js:657:25)
Emitted 'error' event at:
    at emitErrorNT (internal/streams/destroy.js:82:8)
    at emitErrorAndCloseNT (internal/streams/destroy.js:50:3)
    at process._tickCallback (internal/process/next_tick.js:63:19)
npm ERR! code ELIFECYCLE
npm ERR! errno 1

Desired functionality

The cli proxy dev server should support returning websocket errors to the client instead of crashing.

Mention any other details that might be useful

[Halynsky]

Same

[SimonSch]

+1

[sysheap]

+1

[pmouawad]

Hello,
Facing same issue with following configuration:

`
Angular CLI: 7.3.6
Node: 10.15.3
OS: darwin x64
Angular: 7.2.9
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router

Package Version

@angular-devkit/architect 0.13.6
@angular-devkit/build-angular 0.13.6
@angular-devkit/build-optimizer 0.13.6
@angular-devkit/build-webpack 0.13.6
@angular-devkit/core 7.3.6
@angular-devkit/schematics 7.3.6
@angular/cdk 7.3.4
@angular/cli 7.3.6
@angular/material 7.3.4
@angular/material-moment-adapter 7.3.7
@ngtools/webpack 7.3.6
@schematics/angular 7.3.6
@schematics/update 0.13.6
rxjs 6.3.3
typescript 3.2.4
webpack 4.29.0`

Proxy configuration is :

var process = require("process");
var BACKEND_PORT = process.env.BACKEND_PORT || 8443;
const PROXY_CONFIG = [
  {
    context: ["/api"],
    target: "https://localhost:" + BACKEND_PORT,
    secure: false,
    logLevel: "info"
  },
  {
    context: ["/event"],
    target: "wss://localhost:" + BACKEND_PORT,
    ws: true,
    secure: false,
    logLevel: "info"
  },
];
module.exports = PROXY_CONFIG;

Whenever Backend is stopped, ng server crashes with:

[HPM] Error occurred while trying to proxy request /event from localhost:4200 to wss://localhost:8443 (ECONNREFUSED) (https://nodejs.org/api/errors.html#errors_common_system_errors)
events.js:174
      throw er; // Unhandled 'error' event
      ^

Error: read ECONNRESET
    at TLSWrap.onStreamRead (internal/stream_base_commons.js:111:27)
Emitted 'error' event at:
    at emitErrorNT (internal/streams/destroy.js:82:8)
    at emitErrorAndCloseNT (internal/streams/destroy.js:50:3)
    at process._tickCallback (internal/process/next_tick.js:63:19)

Same issue occurs on Windows 10.

Thanks in advance for any help.
Regards

[cod-e-ash]

+1

[apocalyp0sys]

As a workaround, you can put

var process = require('process');

process.on('uncaughtException', function(err) {
    // Prevent ECONNRESET errors
    // handle the error safely
    console.log(err)
});

somewhere in ng serve script,
for example in node_modules/@angular/cli/commands/serve-impl.js

[davidstellini]

Same issue.
@apocalyp0sys The workaround involves editing node modules, right? I'm trying to figure out something better without ejecting.

[maciaszczykm]

Is there a chance to raise the priority of this issue? Do you know any workarounds different than editing module code directly?

cc @filipesilva