GenType Recursive TypeDefs (Bug?)

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1

Hey folks, I’ve got a recursive type definition that looks like

  // Inside module "Node"
  @genType
  type rec t = {
    kind: kind,
    props: props,
    children: array<t>,
  }
  @genType
  and kind =
    | Primitive(string)
    | Composite(compositeFactory)
  @genType
  and compositeFactory = (renderContext, props, array<t>) => t

and my Typescript output is the following:

export type Node_t = {
  readonly kind: kind; 
  readonly props: Node_props; 
  readonly children: Node_t[];
};

// tslint:disable-next-line:interface-over-type-literal
export type Node_kind = 
    { tag: "Primitive"; value: string }
  | { tag: "Composite"; value: compositeFactory };

// tslint:disable-next-line:interface-over-type-literal
export type Node_compositeFactory = (_1:Node_renderContext, _2:Node_props, _3:Node_t[]) => Node_t;

The generated typedefs are almost perfect here, but notice that the generated type Node_t has a property kind of type kind but there is no generated type kind, it’s called Node_kind (and same thing with compositeFactory). Am I doing something wrong here? Or is this perhaps a genType bug?

2

Are you getting any warnings? This issue suggests that type rec isn’t very well supported due to inherent complexities. But if that’s not related then I think logging a bug there is the next step.

3

I think it’s actually a bug to do with module scope. I just found that if I move my Node module code out into its own file named Node.res, genType produces well-formed typescript output.

Interestingly, doing so raises a different problem. Previously, genType was generating types with names like Node_t, now it’s just generating types named t. For my end users, I think it would be nice to just rename that type to just Node, which I tried doing via

  @genType.as("Node")
  type rec t = {
    kind: kind,
    props: props,
    children: array<t>,
  }
  and kind =
    | Primitive(string)
    | Composite(compositeFactory)
  and compositeFactory = (renderContext, props, array<t>) => t

This works, but the typescript produced is

export declare type t = {
    readonly kind: kind;
    readonly props: props;
    readonly children: t[];
};
export declare type Node = t;

All of my ReScript functions which deal with this type t present their types as t rather than as Node, so any end-user’s IDE intellisense will speak in “t” rather than in type “Node”. Is there a way around that with genType?

Obviously I could literally rename this type in my Rescript, but that seems to break with idiomatic ReScript

4

I think I’ve hit the same issue once, I’m pretty sure it’s a bug.