`finally` is not a function error hit with `_getServerWorkingDir`

[rcjsuen]

TypeError this._getServerWorkingDir(...).then(...).finally is not a function 
    extension.js:1:395787 d.createMessageTransports
    extension.js:1:226888 d.createConnection
    extension.js:1:217342 d.start
    extension.js:1:130234 _

vscode-languageserver-node/client/src/node/main.ts

Lines 573 to 589 in df56e72

	private _getServerWorkingDir(options?: { cwd?: string }): Promise<string | undefined> {
	let cwd = options && options.cwd;
	if (!cwd) {
	cwd = this.clientOptions.workspaceFolder
	? this.clientOptions.workspaceFolder.uri.fsPath
	: this._mainGetRootPath();
	}
	if (cwd) {
	// make sure the folder exists otherwise creating the process will fail
	return new Promise(s => {
	fs.lstat(cwd!, (err, stats) => {
	s(!err && stats.isDirectory() ? cwd : undefined);
	});
	});
	}
	return Promise.resolve(undefined);
	}

I see this error in the telemetry of our VS Code extension. If I try to search the error on the Internet, I can find a single StackOverflow post talking about the same thing. I have looked at the code and tried writing a small JavaScript program but can't quite figure out in what case this might happen. We are on 9.0.1 of vscode-languageclient.

[dbaeumer]

@rcjsuen is this still an issue for you?

[rcjsuen]

is this still an issue for you?

@dbaeumer Yes. I still see the error every day in our telemetry across all three major operating systems.

[dbaeumer]

I looked at the code and I have honestly no idea what is causing it. Do you know if you do anything special with working directories?

[rcjsuen]

I looked at the code and I have honestly no idea what is causing it. Do you know if you do anything special with working directories?

No, we don't. The client options code can be found here. The telemetry shows that vscode.env.appHost is "desktop" but my suspicions right now are:

• strange workspace folder (with some non-standard URI?)
• no workspace folder
• says "desktop" but is actually Codespaces or some other custom cloud environment
• JavaScript packaging/webpack causing promise weirdness

The StackOverflow post seems to suggest they were hitting it on the JSON language server so even a "standard installation" is triggering it.

I am getting the following when I open VSCode with a Salesforce Lightening Web Components project.

I don't understand this bit though and how that would trigger this error...

[VoloviZzz]

I managed to solve the problem only by clearing all vs code files.

rm -fr ~/Library/Preferences/com.microsoft.VSCode.helper.plist
rm -fr ~/Library/Preferences/com.microsoft.VSCode.plist
rm -fr ~/Library/Caches/com.microsoft.VSCode
rm -fr ~/Library/Caches/com.microsoft.VSCode.ShipIt/
rm -fr ~/Library/Application\ Support/Code/
rm -fr ~/Library/Saved\ Application\ State/com.microsoft.VSCode.savedState/
rm -fr ~/.vscode/
rm -rf ~/.vscode*

[dbaeumer]

Could it be that a different Promise libary is used that doesn't have finally.

I could change the code to use try { } finally { } instead but I would like to understand why it is failing