Pseudoterminal output does not appear f emitted before open() event fires

[DanTup]

Not sure what's happening here, but content written to an emitter for a pseudo terminal doesn't seem to show up outside of the open function:

const emitter = new vs.EventEmitter<string>();
const pseudoterminal: vs.Pseudoterminal = {
	close: () => { },
	onDidWrite: emitter.event,
	open: () => { emitter.fire("Hello world!\r\n"); },
};
const terminal = vs.window.createTerminal({ name: `Danny Test Terminal`, pty: pseudoterminal });
emitter.fire(`Test 1\r\n`);
terminal.show();
emitter.fire(`Test 2\r\n`);
setTimeout(() => emitter.fire(`Test 3\r\n`), 100);

I only see the first line in the terminal:

[DanTup]

Seems like this may be a delay in the terminal subscribing to the event. Unsure if this is a bug/unintended race, or by design (if intended, I think it should be documented against the API somewhere).

This works:

const emitter = new vs.EventEmitter<string>();
let terminal!: vs.Terminal;
const terminalCreation = new Promise((resolve) => {
	const pseudoterminal: vs.Pseudoterminal = {
		close: () => { },
		onDidWrite: emitter.event,
		open: () => { emitter.fire("Hello world!\r\n"); resolve(); },
	};
	terminal = vs.window.createTerminal({ name: `Danny Test Terminal`, pty: pseudoterminal });
});
await terminalCreation;
terminal.show();
setTimeout(() => emitter.fire("Test 3\r\n"), 0);

[Tyriar]

I think it's by design, open is the callback when everything is ready, you should only write after open is called.

[DanTup]

Daniel Imms (@Tyriar) my suggestion above was that if this was by-design, it was called out in the docs. It's difficult to know when things are bugs or not if they're only documented in GH issues that are really difficult to search and may just result in more people filing issues (or, having bugs).

[Tyriar]

Will do, thanks