Volar fails to start in eclipse theia

[mind-ar]

Volar fails to start in eclipse theia because cant find typescript module:

Message: Request initialize failed with message: Can't find typescript.js or tsserverlibrary.js in

after some investigation, i found that volar is trying to load the typescript module from extensions/node_modules, that seems to be the place where vscode contains this module.

volar.js/packages/vscode/lib/features/tsVersion.ts

Lines 156 to 166 in cd3695a

	if (vscode.env.appRoot) {
	const libPath = path.join(
	vscode.env.appRoot.replace(/\\/g, '/'),
	'extensions/node_modules/typescript/lib',
	);
	return {
	path: libPath,
	version: await getTsVersion(libPath),
	isWeb: false,
	};
	}

there's a workaround, installing the ms-vscode.vscode-typescript-next extensions, that uses extensionPath to find the node_modules folder (i think that extensionPath is empty so it use the node_modules from de theia folder)

volar.js/packages/vscode/lib/features/tsVersion.ts

Lines 143 to 154 in cd3695a

	const nightly = vscode.extensions.getExtension('ms-vscode.vscode-typescript-next');
	if (nightly) {
	const libPath = path.join(
	nightly.extensionPath.replace(/\\/g, '/'),
	'node_modules/typescript/lib',
	);
	return {
	path: libPath,
	version: await getTsVersion(libPath),
	isWeb: false,
	};
	}

here's the related issue in theia repo: eclipse-theia/theia#12443

is there any chance to add a fix to this problem (ie, validating that the extensions/node_modules exists)?

Thanks

[remcohaszing]

Volar needs to be able to load TypeScript. Does Theia provide this in some other way?

Note that crash happens in a fallback mechanism. Typically users set the typescript.tsdk option in their VS Code settings.

[msujew]

@remcohaszing Theia project lead here. Since adopters can use any set of vscode extensions they like, there is no guarantee that a Theia app ships with a TypeScript distribution. IMO the best fix would be to just specify in the error that the typescript.tsdk needs to be set in the project settings.