Variable ASYNC_NONE`Const`

ASYNC_NONE: Promise<None> = ...

Async Option constant for None. A pre-resolved Promise<None> that can be reused to avoid creating new Promise instances when returning None from async functions.

Since None extends Option<never>, this constant can be assigned to any AsyncOption<T> (i.e., Promise<Option<T>>) due to TypeScript's covariance.

Since

1.8.0

Example

async function findUser(id: number): AsyncOption<User> {
    if (id < 0) {
        return ASYNC_NONE;
    }
    const user = await db.findUser(id);
    return user ? Some(user) : ASYNC_NONE;
}

Example

// Useful in conditional async returns
function maybeLoadAsync(shouldLoad: boolean): AsyncOption<Data> {
    if (!shouldLoad) {
        return ASYNC_NONE;
    }
    return loadDataAsync();
}

Variable ASYNC_NONEConst

Since

Example

Example

Settings

Variable ASYNC_NONE`Const`