Add missing types, fix remaining faulty ones

[rekmarks]

I missed a couple of errors in #66. While fixing them, I decided to add types for all exports as well.

[rekmarks]

This was one of the errors. You can actually pass errors to the return handler callbacks in order to cause the JSON-RPC request to return an error.

[rekmarks]

This one is a little iffy. Really, I want to type it like: if it's a function, then it has to extend JsonRpcMiddleware, otherwise it can be anything.

OTOH, even that is perhaps a bit too permissive, since the values should probably be serializable 🤔

[brad-decker]

Maybe something like this? I think what you have is correct but just throwing out another possibility to look into.

type Serializable = boolean | number | string | Record<string, unknown> | unknown[] | null | undefined;
type ScaffoldMiddlewareHandler<T> = T extends Function ? JsonRpcMiddleware : Serializable;

export interface createScaffoldMiddleware<T> {
  (handlers: {[methodName: string]: ScaffoldMiddlewareHandler<T>}): JsonRpcMiddleware;
}

[brad-decker]

LGTM, added a thing you could tinker with but its non blocking

[brad-decker]

Maybe something like this? I think what you have is correct but just throwing out another possibility to look into.

type Serializable = boolean | number | string | Record<string, unknown> | unknown[] | null | undefined;
type ScaffoldMiddlewareHandler<T> = T extends Function ? JsonRpcMiddleware : Serializable;

export interface createScaffoldMiddleware<T> {
  (handlers: {[methodName: string]: ScaffoldMiddlewareHandler<T>}): JsonRpcMiddleware;
}

[rekmarks]

@brad-decker, that's a really neat suggestion! I accepted it here: 51f7f9a

[brad-decker]

Woot LGTM