[WIP] feat(unstable): add Deno.openPty and friends

[imjamesb]

Original PR: #14535, github repo got deleted so I had to reopen.

[nayeemrmn]

Add a close() method like other resources have

Suggested change

	export interface Pty {
	rid: number;
	readable: ReadableStream<Uint8Array>;
	writable: WritableStream<Uint8Array>;
	}
	export class Pty {
	readonly rid: number;
	readonly readable: ReadableStream<Uint8Array>;
	readonly writable: WritableStream<Uint8Array>;
	close(): void;
	}

[crowlKats]

@nayeemrmn not all resources have that, ie the new subprocess API does not have a close method. also on that note, the rid should not be exposed either.

[nayeemrmn]

Spawn has alternate ways of closing / being waited on, things that are closed primarily by Deno.close(res.rid) should have a wrapper method.

Hiding rids (even if they're not used for normal API usage) might be a problem for metrics and resource leakage tracking, but I'm not sure if that's practically a problem especially with our better sanitizer messages. Sure, I agree with hiding rid in a weak map for now.

[crowlKats]

I agree with hiding rid in a weak map for now.

instead of a weakmap, it should be a symbol (as we do with web apis), for consistency.

overall, from what i remember discussing a few months back, we would want to move away from allowing manual resource management (so closing a resource and other usages of resource ids)

[imjamesb]

@nayeemrmn I suppose that this method will use core.tryClose() under the hood?

[nayeemrmn]

Accept the Pty object directly, unwrap the rid when calling the op

Suggested change

	* tty: pty.rid,
	* tty: pty,

[nayeemrmn]

Deno's later APIs, while not hiding the rid, are designed to be usable without referencing them. See Deno.HttpClient:

const client = Deno.createHttpClient({ caCerts: [ caCert ] });
const req = await fetch("https://myserver.com", { client });
client.close();

[imjamesb]

So I think the PR should be complete Unix wise, maybe some tests is needed first. I'll start getting work done on the Windows features ASAP.

[imjamesb]

My PC's network card is broken. Can't work on the Windows implementation. I'll go fetch my work laptop in a couple of days to continue working on this.

[imjamesb]

I got my network card working, just doing some research on conpty, just need to learn the infrastructure around it for Windows.

[imjamesb]

For reference:

https://discord.com/channels/684898665143206084/688040863313428503/1009118094632951879

[imjamesb]

Another thing that should be taken into consideration if PTY's are moved into spawn API is that consoleSize() should get the PTY console size for the attached process, which will cause issues if implemented incorrectly on Linux, but will work ok on Windows. And then consoleResize which should resize the PTY, so in this case the operation should be applied to the PTY and not the process. I think that some changes are required in jsland to support those new features.

[imjamesb]

Just because I want this so bad I will take another shot at implementing this into the spawn API and also introduce a new tty function, Deno.consoleResize().

edit: Nevermind #15641