switchcase.ts

// Implementation
// ---------------
interface Cases<V> {
    [value: string]: Resolver<V>;
    default: Resolver<V>;
}
type Resolver<V> = () => V;
const switchcase = <V extends any>(value: string | number, cases: Cases<V>): V =>
    cases[value in cases ? value : 'default']();

// Usage
// ---------------
const determine = (user: any) => switchcase(user, {
    elisa: () => 'mother',
    nora: () => 'daugher',
    robin: () => 'father',
    default: () => 'who?',
});

const res = determine('elisa')