CODEWITHSUNDEEP
enumstypescript
vbezhenar
vbezhenar

Reputation: 12346

Declare enum with global names

I have a Javascript function which accepts a number. Also there are some top-level constants:

var FOO = 1;
var BAR = 2;

and it only makes sense to call this function using one of these constants.

I want to create a type-safe interface for this function using enum:

declare enum MyType {
    FOO,
    BAR
}

interface MyClass {
    process(MyType type);
}

but this code outputs MyType.FOO in js file. I need it to output just FOO but still be type-safe in typescript code. Is it possible?

Upvotes: 0

Views: 139

Answers (1)

Ryan Cavanaugh
Ryan Cavanaugh

Reputation: 221192

// Version A
const enum _MyType {
    FOO,
    BAR
}
let FOO = _MyType.FOO;
let BAR = _MyType.BAR;

or

// Version B (if FOO and BAR come from another file)
declare const enum _MyType {
    FOO,
    BAR
}
declare let FOO: _MyType;
declare let BAR: _MyType;

Either way,

function fn(x: _MyType) { /* ... */ }

fn(FOO); // OK
fn('quack'); // Error

Upvotes: 2

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