Typescript interface optional properties depending on other property

Question

Let\'s say we have the following Typescript interface:

interface Sample {
    key1: boolean;
    key2?: string;
    key3?: number;
};
         


        

Answer 1

I think that a readable solution is to use overload

so we can do this:

type IOverload = {
  (param: { arg1: number }): any;
  (param: { arg1: number; arg2: string; arg3: number }): any;
};

const sample: IOverload = (args) => {...};

sample({ arg1: 1, arg2: 'a' });

===> Property 'arg3' is missing in type '{ arg1: number; arg2: string; }' but required 
in type '{ arg1: number; arg2: string; arg3: number; }'.