StrictOmit<ObjectType, ExcludedKeys>

Overview

This type is a stricter version of TypeScript's Omit utility type.

Unlike Omit, which allows omission of keys not present on the given type, StrictOmit ensures that only keys actually present in the type can be omitted. This provides a more controlled and predictable type manipulation, preventing unintended omissions of non-existent keys.

Syntax

type StrictOmit<ObjectType, ExcludedKeys extends keyof ObjectType> = Omit<
  ObjectType,
  ExcludedKeys
>;

• ObjectType: The type from which properties will be omitted.
• ExcludedKeys: The keys to be omitted, which must be present in ObjectType.

Examples

Example #1

type Example = {
  a: number;
  b: string;
  c: boolean;
};

type StrictOmittedExample = StrictOmit<Example, 'c'>;
// Result: { a: number; b: string }

TIP

If your team is using ESLint and wants to enforce the use of StrictOmit instead of the standard Omit, you can configure ESLint to help catch this. The @typescript-eslint/ban-types rule can be configured to display an error message when Omit is used, guiding developers to use StirctOmit instead. Here's how you can set up your ESLint configuration:

module.exports = {
  parser: '@typescript-eslint/parser',
  plugins: ['@typescript-eslint'],
  rules: {
    // Include other relevant rules here
    '@typescript-eslint/ban-types': [
      'error',
      {
        types: {
          Omit: 'Use StrictOmit instead',
        },
        extendsDefaults: true,
      },
    ],
  },
};