stdio support broken on Windows?

I have the following code that executes my language server and uses stdio as TransportKind: https://github.com/itmuckel/factor-lsp/blob/master/lsp-sample/client/src/extension.ts

        let serverOptions: ServerOptions = {
		command: "C:/factor/factor-lsp/factor-lsp.exe",
		transport: TransportKind.stdio,
	};

	// Options to control the language client
	let clientOptions: LanguageClientOptions = {
		// Register the server for plain text documents
		documentSelector: [{ scheme: 'file', language: 'Factor' }],
		synchronize: {
			// Notify the server about file changes to '.clientrc files contained in the workspace
			fileEvents: workspace.createFileSystemWatcher('**/.clientrc')
		}
	};

	// Create the language client and start the client.
	client = new LanguageClient(
		'languageServerExample',
		'Language Server Example',
		serverOptions,
		clientOptions
	);

	// Start the client. This will also launch the server
	client.start();

This works on Linux (Ubuntu). My LS gets the “initialize” and “shutdown” requests, but no responses come back from it.
On Windows my LS won’t even get the requests from the Client.

Anyone else experienced this and/or have some ideas how to fix this? 🤔

[dbaeumer]

Does the LSP sample work for you under Windows using stdio. https://github.com/microsoft/vscode-extension-samples/tree/master/lsp-sample

[xtttt]

@dbaeumer This issue may be related to this phenomenon. I wrote a C program.

#include <stdio.h>
int main() {
   printf("test\n");
   return 0;
}

And I wrote a nodejs program to call this C program.

var cp = require('child_process');
var child = cp.spawn("a.exe");
child.stdout.on('data', function (data) {
    console.log(data);
});

when i get stdout output, \n characters will be replaced with \r\n

(0d 0a) means \r\n

PS D:\Code> node index.js
<Buffer 74 65 73 74 0d 0a>

The same problem occurs in vscode extension.

LSP Message The header part includes the ‘\r\n’ separating the header and content part. When \n is converted to \r\n, the original \r\n is changed to \r\r\n. As a result, the format is incorrect, and the connection using the stdio process fails.

I don’t know why this happened, but it seems to be related to this issue. Can someone please explain it to me?