array-util.ts

import { match, Pattern } from 'ts-pattern'

/**
 * Returns an element of the array matching given pattern or `null`
 */
export const find = <T>(data: T[], query: Pattern<T>): T | undefined =>
	data
		.find(item =>
			match(item)
				.with(query, () => true)
				.otherwise(() => false)
		)


/**
 * Returns the index of an element in the array
 * matching given pattern or `undefined`
 */
export const findIndex = <T>(data: T[], query: Pattern<T>): number =>
	data
		.findIndex(item =>
			match(item)
				.with(query, () => true)
				.otherwise(() => false)
		)


/**
 * Updates an array element matching given pattern
 */
export const update = <T>(data: T[], query: Pattern<T>, update: Partial<T>): T[] =>
	data
		.map( item =>
			match(item)
				.with(query, () => ({ ...item, ...update }))
				.otherwise(() => item)
		)

/**
 * Removes an array element matching given pattern
 */
export const remove = <T>(data: T[], query: Pattern<T>): T[] =>
	data
		.filter(
			item =>
				match(item)
					.with(query, () => false)
					.otherwise(() => true)
		)

Example Usage:

type Person = {
	id: number;
	name: string;
	age: number;
}


let people: Person[] = [{
	id: 1,
	name: 'John Doe',
	age: 30
}, { 
	id: 2,
	name: 'Elisa Doe',
	age: 32
}]

people = update(people, { age: 30 }, { age: 35 })

const person = find(people, { name: 'John Doe' })

console.log(`${person.name} is ${person.age}`) //=> "John Doe is 35"