nullish-math

nullish-math is a lightweight TypeScript package that provides basic math operations with support for null and undefined values and an immutable, chainable API. It is useful when working with numeric data that may contain nullish values, as it ensures that any calculations involving nullish values result in null values.

Installation

To install nullish-math, use one of the following commands:

bun add nullish-math
npm install nullish-math
pnpm add nullish-math
yarn add nullish-math

Usage

To use nullish-math, simply import the nm() function from the package:

import { nm } from 'nullish-math'

You can then use the nm() function to create a new NullishMath object with an initial value:

const value = nm(42)

You can chain together multiple math operations using the add(), subtract(), multiply(), and divide() methods:

const result = nm(42).add(21).multiply(2).subtract(10).end() // 116

// null results in null
const result = nm(42).add(null).multiply(2).subtract(10).end() // null

// undefined results in null
const result = nm(undefined).add(21).multiply(2).subtract(10).end() // null

If any of the values passed to the math operation methods (add(), subtract(), multiply(), divide()) are nullish, the final value will be null.

API

nm(value: number | null | undefined): NullishMath

The nm() function creates a new NullishMath object with an initial value.

add(number: NullishMath | number | null | undefined): NullishMath

Returns a new instance of NullishMath with the sum of the current value and the given number.

addMany(...nums: Array<NullishMath | number | null | undefined>): NullishMath

Returns a new instance of NullishMath with the sum of the current value and the given numbers.

eq(toCompare: NullishMath | number | null | undefined): boolean

Returns true if the result equals toCompare, treats null and undefined as equals.

lt(toCompare: NullishMath | number | null | undefined): boolean | null

Returns true if the result is strictly less than toCompare, returns null if either number is nullish.

lte(toCompare: NullishMath | number | null | undefined): boolean | null

Returns true if the result is less than or equal to toCompare, returns null if either number is nullish.

gt(toCompare: NullishMath | number | null | undefined): boolean | null

Returns true if the result is strictly greater than toCompare, returns null if either number is nullish.

gte(toCompare: NullishMath | number | null | undefined): boolean | null

Returns true if the result is greater than or equal to toCompare, returns null if either number is nullish.

neq(toCompare: NullishMath | number | null | undefined): boolean

Returns true if the result doesn’t equal toCompare, treats null and undefined as equals.

subtract(number: NullishMath | number | null | undefined): NullishMath

Returns a new instance of NullishMath with the difference of the current value and the given number.

subtractMany(...nums: Array<NullishMath | number | null | undefined>): NullishMath

Returns a new instance of NullishMath with the difference of the current value and the given numbers.

multiply(number: NullishMath | number | null | undefined): NullishMath

Returns a new instance of NullishMath with the product of the current value and the given number.

multiplyMany(...nums: Array<NullishMath | number | null | undefined>): NullishMath

Returns a new instance of NullishMath with the product of the current value and the given numbers.

divide(number: NullishMath | number | null | undefined): NullishMath

Returns a new instance of NullishMath with the quotient of the current value and the given number.

divideMany(...nums: Array<NullishMath | number | null | undefined>): NullishMath

Returns a new instance of NullishMath with the quotient of the current value and the given numbers.

end(): number | null

Returns the final value of the NullishMath instance. If any of the values passed to the math operation methods are null or undefined, the final value will be null.

NullishMath.average(Array<NullishMath | number | null | undefined>, options?: { treatNullishAsZero?: boolean }): number | null

Calculates the average of the provided numbers. By default, nulls are excluded from the average. This can be changed by setting the treatNullishAsZero option. With this flag, nullish numbers get counted as a 0 and thus impact the average.

Returns null on division by zero unless treatNullishAsZero is set (in which case it returns 0).

NullishMath.unwrap(NullishMath | number | null | undefined): number | null

Converts the input to either number | null. General-purpose equivalent of nm.end()

Development

nullish-math uses bun

bun install
# bun run test