todo.js

'use strict'

let data = []

module.exports.clear = () => {
	if(data.length === 0) throw new Error('trying to clear empty list')
	data = []
}

module.exports.add = (item, qty) => {
	item = item.toLowerCase()
	if(item.length === 0) {
		throw new Error('item is blank string')
	}
	if (typeof qty !== 'number') qty = 1
	let listItem = data.find(elem => elem.item==item)
	if (listItem) {
		listItem.qty +=qty
	}
	else {
		data.push({item: item, qty: qty})
	}
}

module.exports.getAll = () => {
	if(data.length === 0) throw new Error('empty list')
	for(const key in data) data[key].key = key
	return data
}

module.exports.delete = key => {
	console.log(`delete key ${key}`)
	return
}