OptionalExcept type

[stabai]

A common use case of making a Partial of an object, but leaving a few keys as is.

export type OptionalExcept<Type, AsIsKeys extends keyof Type> = Pick<Type, AsIsKeys> & Partial<Omit<Type, AsIsKeys>>;

Example:

interface User {
  username: string;
  isAdmin: boolean;
  dateCreated: Date;
}

function newUser(userOptions: OptionalExcept<User, 'username'>): User {
  return {
    // Default values for optionals (if specified in userOptions, will be overwritten)
    isAdmin: false,
    dateCreated: new Date(),

    // Specified values (including the username, which we kept as required)
    ...userOptions
  };
}

Upvote & Fund

• We're using Polar.sh so you can upvote and help fund this issue.
• The funding will be given to active contributors.
• Thank you in advance for helping prioritize & fund our backlog.

[voxpelli]

I guess this can be achieved somewhat by doing SomeOptional<User, Omit<keyof User, 'username'>> – maybe that's enough?

[stabai]

Oh, yes, that would work, I hadn't thought of that formulation. I may be misunderstanding the suggested types, but I think it would be like this:

SetOptional<User, Exclude<keyof User, 'username'>>