#unless

Returns a function that applies a transform only when a predicate fails, otherwise returns the value unchanged.

Complement of when.

const ensureArray = unless(Array.isArray, (v) => [v])
ensureArray(42) // [42]
ensureArray([1]) // [1]

#Usage

#unless<T>(predicate: (value: T) => boolean, fn: (value: T) => T)

Returns a function that applies a transform only when a predicate fails, otherwise returns the value unchanged.

Complement of when.

import { unless } from 'massaman'
// or:  import { unless } from 'massaman/function'

const ensureArray = unless(Array.isArray, (v) => [v])
ensureArray(42) // [42]
ensureArray([1]) // [1]

#Parameters

#Returns

a function that transforms values only when predicate returns false.

(value: T) => T