rain84

export const compose = (...fns) => (...args) =>
	fns.reduceRight((args, fn) => fn(...(Array.isArray(args) ? args : [args])), args)

export const composeRecursive = (...fns) => {
	const last = fns.pop()
	if (!fns.length) return (...args) => last(...args)

	const prev = fns.pop()
	fns.push((...args) => {
		let res = last(...args)

rain84

import { maxSubArray, addToSet } from './max-sub-array.airbnb'

describe('MaxSubArray', () => {
	let arr = []

	test('should return on empty array', () => {
		expect(maxSubArray(arr)).toBeUndefined()
	})

	test('should work on array.length === 1', () => {

rain84

import { equalChunks, getChunkIndexes, extractByIndexes, ResultType } from './equalChunks'

describe('equalChunks', () => {
    const helpers = {
        sum: (arr: number[]) => arr.reduce((a, b) => a + b),
        have3equalChunks: (arr: ResultType) => arr.every((item) => helpers.sum(item) === helpers.sum(arr[0])),
    }

    test('should return null on empty array', () => {
        expect(typeof equalChunks).toBe('function')

rain84

import { asyncParallel } from './asyncParallel'

const fakedFetch = (timeout: number) => new Promise((resolve) => setTimeout(() => resolve(timeout), timeout * 1000))

describe('fakedFetch', () => {
	test('should retun Promise', () => {
		expect(fakedFetch(1) instanceof Promise).toBeTruthy()
	})

	test('should asyncronously retun value after delay', async () => {

rain84

import {useState, useEffect, Component} from 'react'

const ErrorBlock = ({error: e, onReload}) => (
    <div>
        <div role="alert">
            There was an rejected: {e?.message && <pre style={{whiteSpace: 'normal'}}>{e.message}</pre>}
        </div>
        <button onClick={onReload}>Reload page</button>
    </div>
)