Falsy

added in 0.4.0 • last revisions

Syntax

type Falsy<T = unknown>

Attempts to extract all falsy values from a type.

Example

import { Falsy } from 'potence';

type A = Falsy<0 | 1 | '' | 'a'>;  // -> 0 | ''
type B = Falsy<boolean>;           // -> false
type C = Falsy<number>;            // -> 0
type D = Falsy<unknown>;           // -> false | 0 | 0n | "" | null | undefined
type E = Falsy<1 | 'a'>;           // -> never

Remarks

Note that there is currently no way to express NaN as part of a numeric literal (in fact, any value of NaN is automatically inferred as number), so Falsy<T> will not extract NaN from a type.

Click here for more information on “falsiness” as a concept.