Ability to make a field on exported sturct as enumerable

[ranile]

Motivation

I recently ran into this issue where I exported a struct like (original sturct that was used)

#[wasm_bindgen]
pub struct Foo {
    pub bar: Option<bool>,
    // ...
}

and returned it from a function. When the function was called from javascript, the returned value of the function was destructed like (snippet from here)

validity = {...validity, ...customValidity};

where customValidity is the said returned value, the values of struct's fields were assigned on prototype as getters and setters and were not enumerable. Since destructuring only reads the enumerable proprety keys, those values were not available on the final object, validity in this case.

Proposed Solution

Have a attribute that marks a property as enumerable like such

#[wasm_bindgen]
struct Foo {
  #[wasm_bindgen(enumerable)]
  bar: String,
}

This value will then be set as an enumerable property on the resulting javascript object

Alternatives

Use getters and setters to assign the properties on the object manually but obviously this adds a lot of boilerplate.

Additional Context

console.log of returned value from function:

Object.keys of returned value:

After destruction:

`

I hope I made the issue clear. Let me know if any clarification is needed.

[codingstar]

I ran into the same issue