Deep Utility Types

June 2023 GitHub NPM

Utility types for operations on nested objects. Fully type-safe, nice autocompletion, and even works with arrays.

Creating this library really allowed me to get deep into working with TypeScript’s type system. I later used a lot of what I learned here to create the type-safe query API of Crockpot.

import { DeepOmit } from 'deep-utility-types';

type Example = {
  foo1: string;
  foo2: {
    bar1: string;
    bar2: {
      baz1: string;
      baz2: string;
    };
  };
};

type Omitted = DeepOmit<Example, 'foo2.bar1' | 'foo2.bar2.baz1'>;

const omitted: Omitted = {
  foo1: 'foo1',
  foo2: {
    bar2: {
      baz2: 'baz2',
    },
  },
};

More examples can be found in the README.