How to define prop type which takes only true for typescript

[Srikanth Kyatham]

Hi

This is a cross post from rescript-forum. I didnot get an solution which worked. Seeking guidance.
https://forum.rescript-lang.org/t/how-to-define-prop-type-which-takes-only-true/1527

I am trying to write bindings for Textinput in the text-input.d.ts
indent preformatted text by 4 spaces

interface TextInputAutosizeProps
    extends TextInputCoreProps,
        Omit<TextareaAutosizeProps, 'children' | 'ref' | 'type'> {
    autosize: true;
    maxRows?: number;
    rows?: number;
}

The bindings I have written so far

module TextInput = {
   type textInputType = [#Email | #Number | #Password | #Tel | #Text | #Url]
   type unitPosType = [#Inside | #Outside]
  @genType.import(("@myorg", "TextInput")) @react.component
  external make: (
    ~amount: bool=?,
    ~autosize: bool=?,
    ~changed: bool=?,
    ~disabled: bool=?,
    ~hasFocus: bool=?,
    ~invalid: bool=?,
    ~maxLength: int=?,
    ~maxRows: int=?,
    ~readonly: bool=?,
    ~rows: int=?,
   ~size: int=?,
   ~type_: @string
   ...
 )=> React.element = "TextInput" 
 }

How to annotate autosize prop type. Please help

The solutions offered were

Solution1:
Use the @as attribute
module TextInput = { type textInputType = [#Email | #Number | #Password | #Tel | #Text | #Url] type unitPosType = [#Inside | #Outside] @genType.import(("@myorg", "TextInput")) @react.component external make: ( ~amount: bool=?, ~autosize: @as(jsontrue) _=?, }
the resultant type is
readonly autosize: unknown

Solution 2:
module Autosize: { type t let autosize: t } = { type t = bool let autosize = true }
the resultant type is
readonly autosize: Autosize_t;

export abstract class Autosize_t { protected opaque!: any }; /* simulate opaque types */

[Cristiano Calcagno]

@srikanthkyatham here's an example: #545

If I understood the question correctly, it might do what you want.
It requires defining the type true_ somewhere in the project in a TS file.

[Srikanth Kyatham]

@cristianoc yes it solves the issue. Thanks for the solution