JS String Enums and bindings

1

Hi!

I am binding an external module, specifically a function that accepts 3 possible string values at runtime, I want to type it correctly by only allowing those 3 values, but I can’t find a way to do it.

This is what I have right now, which works but its type is string, not environment.:

@deriving(jsConverter)
type environment = [
  | @as("dev") #Dev
  | @as("stage") #Stage
  | @as("prod") #Prod
]

type configuration = {environment: string} // It should type `environment`

@module("data-sdk") external setConfiguration: configuration => unit = "setConfiguration

setConfiguration({
  environment: environmentToJs(#Stage),
})

It is there a way where I can use a type different than string for the environment key?

Thanks!

Edit: The data-sdk dependency is an ES6 module, which also have TS .d.ts typings available.

2

Since polymorphic variants are compiled to strings anyway, why would you want to use jsConverter for this?

type environment = [
  | #dev
  | #stage
  | #prod
]

type configuration = {environment: environment}

@module("data-sdk") external setConfiguration: configuration => unit = "setConfiguration"

setConfiguration({ environment: #stage })

Playground link

4 Likes
3

Thank you! Will read more about these polymorphic variants :slight_smile:

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