ref: Properly type tracing channels

[Luca Forstner (lforst)]

This PR adds a type system to the plugins so that we have e2e typed tracing channels. This should allow us to hopefully migrate the rest of the wrappers to diagnostics channels more easily and safely.

• Adds a defineChannels helper that allows for configuring a list of channels that can be passed directly as a generic type to the base plugin
• The return value of the defineChannels function exposes the channels as fields which in return expose tracingChannel() and tracePromise() as helper functions to emit tracing events. These functions are fully typed and compatible with the plugins if the type is passed in properly.

Closes #1502

[Abhijeet Prasad (AbhiPrasad)]

Why do we have both name and fullName? Can't we derive one from the other?

[Luca Forstner (lforst)]

It's very valid you bring this up cause this I was the most hesitant with.

It's either:

• You provide the short form, ie chat.completions.create and we prefix it with orchestrion:openai:, which is a bit tricky because orchestrion decides by itself what the {pkg} in orchestrion:{pkg}: would be.
• We provide the long form, ie orchestrion:openai:chat.completions.create, but then we have to dynamically strip away the orchestion:openai: prefix which I found a bit nasty too

So my through process was: Screw it, providing both is not too hard and also leaves very little room for (runtime) error.

[Abhijeet Prasad (AbhiPrasad)]

Maybe we can have a defineChannels API that looks like so?

export function defineChannels<T extends Record<string, { channelName: string; kind: ChannelKind }>>(
  pkg: string,
  specs: T,
): { [K in keyof T]: TypedChannel<...> } {
  return Object.fromEntries(
    Object.entries(specs).map(([key, spec]) =>
      [key, channel({
        ...spec,
        fullChannelName: `orchestrion:${pkg}:${spec.channelName}`,
      })]
    )
  );
}

export const openAIChannels = defineChannels("openai", {
  chatCompletionsCreate: { channelName: "chat.completions.create", kind: "async" },
});

[Luca Forstner (lforst)]

I like that

[Luca Forstner (lforst)]

implemented

[Abhijeet Prasad (AbhiPrasad)]

nice! the type safety feels way better