Theo's Typesafe Cult•3y ago

Require one of two properties

What would you folks say is a clean way to accomplish that either userToken or ConversationId are set in my type without requiring both? 🤔

export type PostChatData = {
  command: Extract<ChatCommand, 'POST'>;
  userToken: string;
  conversationId: string;
  type: ChatType;
  // other crap
};

export type PostChatData = {
  command: Extract<ChatCommand, 'POST'>;
  userToken: string;
  conversationId: string;
  type: ChatType;
  // other crap
};

14 Replies

deforestor•3y ago

Interesting question, it seems like no matter what we do, it won't be 100%, but you can achieve it like this:

deforestor•3y ago

but no matter what I try, it'll always show the other one:

deforestor•3y ago

But at least you get an error if you do fill it

WezterOP•3y ago

I need to use that logic in like 10 different types for a lot of my request models, I'll try this suggestion but seems a bit ugly to have to add both types to all the types 🤔 @deforestor what do you think about this?

type RequireAtLeastOne<T, Keys extends keyof T = keyof T> = Pick<T, Exclude<keyof T, Keys>> &
  {
    [K in Keys]-?: Required<Pick<T, K>> & Partial<Pick<T, Exclude<Keys, K>>>;
  }[Keys];

type ConversationIdOrUserToken = RequireAtLeastOne<ChatAuth, 'userToken' | 'conversationId'>;

type RequireAtLeastOne<T, Keys extends keyof T = keyof T> = Pick<T, Exclude<keyof T, Keys>> &
  {
    [K in Keys]-?: Required<Pick<T, K>> & Partial<Pick<T, Exclude<Keys, K>>>;
  }[Keys];

type ConversationIdOrUserToken = RequireAtLeastOne<ChatAuth, 'userToken' | 'conversationId'>;

And then I just do & ConversationIdOrUserToken to all of them.

deforestor•3y ago

I tried that one too, but..

deforestor•3y ago

it doesn't show me the error

Brendonovich•3y ago

How about this?

export type PostChatData = {
  command: "POST";
} & ({ userToken: string } | { conversationId: string }) & {
    userToken?: string;
    conversationId?: string;
  }

export type PostChatData = {
  command: "POST";
} & ({ userToken: string } | { conversationId: string }) & {
    userToken?: string;
    conversationId?: string;
  }

Could probs be turned into a helper

Brendonovich•3y ago

helper gets a little crazy but it works https://www.typescriptlang.org/play?#code/PTAEAsBdIBwZwFwjpAhgYwNYHsBuBTAJwDMAbbAdwDp1sBbYARwFd8UBLbAOzmAFYADAGYA7ABYAnAIAcwSIVQ9i2QnQC0zLpy5rIATxj5d2Ney6QicfOkjbdB-ACh9h0AFUt3ACrYAkuctrW24AHjcAPlAAXlAACjdQfAAPCy4AEzhQRT1QAH44zAR3AEpoyNxsdjTQIq58AkJS5NSMuMdQUELQM2IiUF9HUqjyyrT2vP7x2vqiAG5HZwdQAEFIABl8VBQAeTqQr0SU-HTM7AAjACsgyJiDgDJ3Ty4ffwtCKxttEIAFVEJbVCkfbhcLzRzJGAqSCgFz4UDfbAoADC4FQkAAImjUNFQABvca0Oh0RRpIoAIm+2wAyl4yfMAL6gB6rDZbSC7fAhXGgZhWQg+TDHIooQhmADmoEZAB88aBaFwGnA0dpfKTQCLxZLQY4gA

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Unknown User•3y ago

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Brendonovich•3y ago

I think it’s from another SO, looks the same tho

Unknown User•3y ago

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WezterOP•3y ago

Wouldn't what I sent earlier work?

type RequireAtLeastOne<T, Keys extends keyof T = keyof T> = Pick<T, Exclude<keyof T, Keys>> &
  {
    [K in Keys]-?: Required<Pick<T, K>> & Partial<Pick<T, Exclude<Keys, K>>>;
  }[Keys];

type ConversationIdOrUserToken = RequireAtLeastOne<ChatAuth, 'userToken' | 'conversationId'>;

type RequireAtLeastOne<T, Keys extends keyof T = keyof T> = Pick<T, Exclude<keyof T, Keys>> &
  {
    [K in Keys]-?: Required<Pick<T, K>> & Partial<Pick<T, Exclude<Keys, K>>>;
  }[Keys];

type ConversationIdOrUserToken = RequireAtLeastOne<ChatAuth, 'userToken' | 'conversationId'>;

And then I just do & ConversationIdOrUserToken to all of them.

deforestor•3y ago

can you show how it looks on the editor?

WezterOP•3y ago

Gaming

Programming

Require one of two properties

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