optional-always-maybe.md

Optional properties must be of type Maybe; (optional-always-maybe)

All optional properties and parameters should be of type Maybe<T>.

Rule Details

This rule aims to ensure that we don't treat null and undefined differently.

Autofixer available.

Examples of incorrect code for this rule:

interface x {
  y?: string;
}

function f(x?: number) {}

Examples of correct code for this rule:

interface x {
  y?: Maybe<string>;
}

function f(x?: Maybe<number>) {}

When Not To Use It

With third-party software that needs to differentiate between null and undefined.