Unexpected "Connection closed" when runing with @wdio/cucumber-framework

[seanpoulter]

Problem

When I use @wdio/cucumber-framework to run my tests
Then I see an unexpected Error: Connection closed. Code: 1006

> wdio run ./test/wdio.conf.ts

Execution of 1 workers started at 2024-02-26T22:11:39.549Z

Skipping download, bundle for ChromeDriver v27.2.3 already exists
Found existing install in .../.wdio-vscode-service/vscode-linux-arm64-1.86.2. Skipping download

[0-0] RUNNING in chrome - file:///test/features/webview.feature
[0-0] file:///.../node_modules/wdio-vscode-service/src/service.ts:60
[0-0]         this._promisedSocket = Promise.reject(new Error(msg))
[0-0]                                               ^
[0-0] Error: Connection closed. Code: 1006, reason: 
[0-0]     at VSCodeWorkerService._handleSocketClose (file:///.../node_modules/wdio-vscode-service/src/service.ts:60:47)
[0-0]     at Object.onceWrapper (node:events:629:26)
[0-0]     at WebSocket.emit (node:events:526:35)
[0-0]     at WebSocket.emit (node:domain:488:12)
[0-0]     at WebSocket.emitClose (.../node_modules/wdio-vscode-service/node_modules/ws/lib/websocket.js:265:10)
[0-0]     at Socket.socketOnClose (.../node_modules/wdio-vscode-service/node_modules/ws/lib/websocket.js:1289:15)
[0-0]     at Socket.emit (node:events:514:28)
[0-0]     at Socket.emit (node:domain:488:12)
[0-0]     at TCP.<anonymous> (node:net:337:12)
[0-0] FAILED in chrome - file:///test/features/webview.feature

Spec Files:      0 passed, 1 failed, 1 total (100% completed) in 00:00:08  

Steps to Reproduce

I've reproduced the error from a private repo in https://github.com/seanpoulter/wdio-vscode-cucumber-example:

nvm install --lts
nvm use --lts
npm ci
npm run test

Analysis

The error is thrown from line 60

wdio-vscode-service/src/service.ts

Lines 58 to 62 in 92b7b6b

	private _handleSocketClose (code: number, reason: Buffer) {
	const msg = `Connection closed. Code: ${code}, reason: ${reason.toString()}`
	this._promisedSocket = Promise.reject(new Error(msg))
	this._pendingMessages.forEach((resolver) => resolver(msg, null))
	}

which is registered on line 116

wdio-vscode-service/src/service.ts

Lines 110 to 117 in 92b7b6b

	wss.on('connection', (socket) => {
	log.info('Connected with VSCode workbench')
	this._promisedSocket = Promise.resolve(socket)
	resolve(socket)
	clearTimeout(socketTimeout)
	socket.on('message', this._handleIncoming.bind(this))
	socket.once('close', this._handleSocketClose.bind(this))
	})

Questions

• Since this._promisedSocket is assigned in beforeSession hook, does it make sense to use the deleteSession hook to reset this._promisedSocket = undefined?
• If this only affects Cucumber, does the solution belong there?

[christian-bromann]

I wonder how the Cucumber execution differs from e.g. Mocha that causes this problem is the first place 🤔

[seanpoulter]

Let me know if you want me to dig into it.

[christian-bromann]

I think we can move forward with the patch #116 .. it's not to crucial for me to get to the bottom of this as long as we document what we are doing in #116 so everyone knows.