Deep Omit with typescript

Question

Is it possible to maintain type coverage on a function that deeply removes all instances of a key in an object?

My function looks like this.

function         


        

Answer 1

For those coming here with a later version of TS (I've tested this with TS3.8.3), you'll need to inline DeepOmitHelper from Titian's answer.

type Primitive =
  | string
  | Function
  | number
  | boolean
  | Symbol
  | undefined
  | null;

type DeepOmitArray = {
  [P in keyof T]: DeepOmit;
};

export type DeepOmit = T extends Primitive
  ? T
  : {
      [P in Exclude]: T[P] extends infer TP
        ? TP extends Primitive
          ? TP // leave primitives and functions alone
          : TP extends any[]
          ? DeepOmitArray // Array special handling
          : DeepOmit
        : never;
    };