Imperfect enum of TypeScript.

[s-shin]

Describe the Bug

enum definition is generated in d.ts from enum type of rust, but the actual code in JS is not compatible with TS. This can cause unexpected errors for example in reverse mappings.

Steps to Reproduce

#[wasm_bindgen]
pub enum Foo {
    A,
    B,
    C,
}

This code will be converted to JS:

export const Foo = Object.freeze({ A:0,B:1,C:2, });

and TS (in d.ts):

export enum Foo {
  A,
  B,
  C,
}

but these are not completely compatible.

Expected Behavior

Consistency should be kept.

Actual Behavior

We can make JS code compatible with TS like this:

export var Foo;
(function (Foo) {
    Foo[Foo["A"] = 0] = "A";
    Foo[Foo["B"] = 1] = "B";
    Foo[Foo["C"] = 2] = "C";
})(Foo || (Foo = {}));

or can also do TS definition compatible with JS.