feat(node/dgram): support dgram (udp) node module compat

[cmorten]

Works towards denoland/deno#18324

• There are a number of APIs that this PR doesn't implement, for the most part because not sure we can right now?
• Some implemented APIs may differ subtly from Node (inevitable perhaps when trying to match JS / Deno interfaces with libuv! 😅).

[bartlomieju]

@cjihrig can you take a look too?

[bartlomieju]

Awesome work, lots of tests enabled! This looks mostly good to me, but I'll wait for review from @cjihrig before landing

[bartlomieju]

Why are these unreachable?

[cmorten]

As far as can see currently these methods exist purely for defining an interface on classes rather than something that will ever be implemented in this compat layer - felt more accurate to fail with unreachable than not implemented.

Wonder whether they should be defined at all… or if we want them, make use of the inheritance better and not override in all of the other wraps. E.g.

// handle_wrap.ts

class HandleWrap {
  handle!: Handle;

  // ... other code

  ref(): void {
    this.handle?.ref()
  }

  unref(): void {
    this.handle?.unref()
  }
}

// tcp_wrap.ts, pipe_wrap.ts, udp_wrap.ts etc.

class X extends HandleWrap {
  methodA() {
    // ...some code
    this.handle = listener;
  }

  // no need to override `ref()` and `unref()`
}

Or perhaps could just exist as:

ref!: () => void;
unref!: () => void;

If we keep with the overrides elsewhere handling these methods.

[kt3k]

LGTM, nice work!

[cjihrig]

LGTM. Nice work!

[kt3k]

@cjihrig Thanks for your review!