instantiated error types not being generated/outputted

[codeliger]

type ErrNotFound error

var (
	ErrFoodNotFound            ErrNotFound = errors.New("food not found")
	ErrCompanyNotFound           ErrNotFound = errors.New("company not found")
	ErrUserNotFound            ErrNotFound = errors.New("user not found")
)

output:

export type ErrNotFound = error;

I am trying to use this common pattern in go, but none of the instantiated errors are being generated
Is there a work around for this @gzuidhof

[gzuidhof]

Hmm there is no obvious way to do it, it's hard for Tygo to have some generic way of dealing with instantiated variables.

I would propose that the most straightforward way is to add some frontmatter manually, you can define frontmatter in the yaml file and it will be put into the output file.

It's not often I see raw error being serialized into Typescript/JSON, I don't even know what it looks like. I guess in the end it becomes a string? In that case, you could use something like the following as frontmatter:

export type error = string;

export const ErrFoodNotFound: error = "food not found";
export const ErrCompanyNotFound: error = "company not found";
export const ErrUserNotFound: error = "user not found";

Of course it's less than ideal to do it manually, but perhaps for your usecase it's fine?

[codeliger]

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error
https://go.dev/blog/error-handling-and-go

In golang an error satisifes this interface

type error interface {
    Error() string
}

I was hoping I could at least create a struct called Error with that interface and assign it. But if I can't use var I will have the same issue.

[codeliger]

I found a good Go article for anyone interested in this issue:
https://dave.cheney.net/tag/errors