Value Helpers

Small helpers that operate on single values: testing for emptiness, bounding a number, and piping a value through a function.

import { blank, clamp, tap } from '@0x26e/utils'

blank

Determines whether the given value is "blank". A value is blank when it is an empty string, a string of only whitespace, null, undefined, an empty object, or an empty array.

function blank(value: any): boolean

Parameters

Parameter	Type	Description
`value`	`any`	The value to test.

Returns boolean — true if the value is blank, false otherwise.

Truth table

Input	Result
`blank('')`	`true`
`blank(' ')`	`true`
`blank(null)`	`true`
`blank(undefined)`	`true`
`blank({})`	`true`
`blank([])`	`true`
`blank(0)`	`false`
`blank(true)`	`false`
`blank(false)`	`false`

Example

blank('') // true
blank('   ') // true (whitespace only)
blank(null) // true
blank({}) // true
blank([]) // true
 
blank(0) // false
blank(false) // false
blank('hello') // false
blank([1, 2]) // false

Blank is not the same as falsy

blank is about emptiness, not falsiness. 0, false, and NaN are falsy in JavaScript but are not blank — they are real values. Whitespace-only strings, on the other hand, are treated as blank.

clamp

Returns a value clamped to the inclusive range of min and max. If the value is below min it returns min; if it is above max it returns max; otherwise it returns the value unchanged.

function clamp(value: number, min: number, max: number): number

Parameters

Parameter	Type	Description
`value`	`number`	The number to clamp.
`min`	`number`	The lower bound of the range.
`max`	`number`	The upper bound of the range.

Returns number — the value bounded to [min, max].

Throws Error — when min is greater than max.

Examples

clamp(5, 1, 10) // 5  (already in range)
clamp(15, 1, 10) // 10 (above max → max)
clamp(-5, 1, 10) // 1  (below min → min)
clamp(5, 5, 5) // 5  (min and max equal)

Throws when min is greater than max

clamp validates its bounds. If min > max, it throws an Error with a descriptive message rather than returning a nonsensical value.

try {
  clamp(5, 10, 1)
} catch (error) {
  console.error(error.message) // 'Minimum (10) is not less than maximum (1).'
}

Note that min === max is allowed — it simply pins the result to that single value.

tap

Invokes an interceptor function with the provided value and returns the interceptor's result. It's a tiny way to pipe a value through a transformation inline.

function tap<T>(value: any, interceptor: (v: any) => T): T

Parameters

Parameter	Type	Description
`value`	`any`	The value passed to the interceptor.
`interceptor`	`(v: any) => T`	A function that receives the value and returns a result.

Returns T — whatever the interceptor returns.

Example

const tappedValue = tap(5, (n) => n * 2)
console.log(tappedValue) // 10

It returns the interceptor's result

Unlike Laravel's tap, which returns the original value, this tap returns whatever the interceptor returns. Use it when you want to transform a value in a single expression — the return type T is inferred from the interceptor.

const name = tap({ first: 'Foysal', last: 'Ahmed' }, (u) => `${u.first} ${u.last}`)
// name === 'Foysal Ahmed'