asyncUnion.ts

type User = {
    login: string,
    avatarUrl: string
};

type PageState = Initial | Retrieving | Success | Error;

type Initial = {
    kind: 'Initial'
};
type Retrieving = {
    kind: 'Retrieving'
};
type Success = {
    kind: 'Success',
    users: User[]
};
type Error = {
    kind: 'Error',
    message: string
};