Improve readablility of isDataValid(data: FilterProps)

[kryr34]

the point is the code is too unreadable, you don't even notice there's a duplicated if (data.minPrice !== null && parseInt(data.minPrice.toString()) < 0)

Originally posted by @kryr34 in #134 (comment)

twp/frontend/src/pages/search/index.tsx

Lines 71 to 214 in 95247e3

	const isValidNumber = (value: string | number | null | undefined): boolean => {
	return typeof value === 'number' || (typeof value === 'string' && !isNaN(parseInt(value)));
	};
	const isInteger = (value: string | number | null | undefined): boolean => {
	return typeof value === 'number' || (typeof value === 'string' && /^-?\d+$/.test(value));
	};
	const isEmpty = (value: string | number | null | undefined): boolean => {
	return value === '' || value === null ? true : false;
	};
	const toNumber = (input: string | null) => {
	if (!input) return null;
	const output = Number(input);
	return isNaN(output) ? null : output;
	};
	const toSortBy = (input: string | null) => {
	switch (input) {
	case 'price':
	return 'price';
	case 'stock':
	return 'stock';
	case 'sales':
	return 'sales';
	case 'relevancy':
	return 'relevancy';
	default:
	return null;
	}
	};
	const toOrderBy = (input: string | null) => {
	switch (input) {
	case 'asc':
	return 'asc';
	case 'desc':
	return 'desc';
	default:
	return null;
	}
	};
	// eslint-disable-next-line react-refresh/only-export-components
	export const isDataValid = (data: FilterProps) => {
	if (typeof data.maxPrice !== 'number' && data.maxPrice !== null && data.maxPrice !== '') {
	if (!isValidNumber(data.maxPrice)) {
	alert('Please enter numbers for max price');
	return false;
	}
	}
	if (typeof data.minPrice !== 'number' && data.minPrice !== null && data.minPrice !== '') {
	if (!isValidNumber(data.minPrice)) {
	alert('Please enter numbers for min price');
	return false;
	}
	}
	if (typeof data.maxStock !== 'number' && data.maxStock !== null && data.maxStock !== '') {
	if (!isValidNumber(data.maxStock)) {
	alert('Please enter numbers for max stock');
	return false;
	}
	}
	if (typeof data.minStock !== 'number' && data.minStock !== null && data.minStock !== '') {
	if (!isValidNumber(data.minStock)) {
	alert('Please enter numbers for min stock');
	return false;
	}
	}
	if (
	(!isInteger(data.maxPrice) && data.maxPrice !== null && data.maxPrice.toString() !== '') ||
	(!isInteger(data.minPrice) && data.minPrice !== null && data.minPrice.toString() !== '') ||
	(!isInteger(data.maxStock) && data.maxStock !== null && data.maxStock.toString() !== '') ||
	(!isInteger(data.minStock) && data.minStock !== null && data.minStock.toString() !== '')
	) {
	alert("can't enter float numbers!");
	return false;
	}
	if (data.minPrice !== null && parseInt(data.minPrice.toString()) < 0) {
	alert("min price can't negative numbers");
	return false;
	}
	if (data.maxPrice !== null && parseInt(data.maxPrice.toString()) < 0) {
	alert("max price can't negative numbers");
	return false;
	}
	if (data.minStock !== null && parseInt(data.minStock.toString()) < 0) {
	alert("min stock can't negative numbers");
	return false;
	}
	if (data.maxStock !== null && parseInt(data.maxStock.toString()) < 0) {
	alert("max stock can't negative numbers");
	return false;
	}
	if (data.minPrice !== null && parseInt(data.minPrice.toString()) < 0) {
	alert("min price can't negative numbers");
	return false;
	}
	if (data.maxPrice !== null && parseInt(data.maxPrice.toString()) < 0) {
	alert("max price can't negative numbers");
	return false;
	}
	if (
	data.maxPrice !== null &&
	data.minPrice !== null &&
	parseInt(data.maxPrice.toString()) < parseInt(data.minPrice.toString())
	) {
	alert("min price can't bigger than max value");
	return false;
	}
	if (
	data.maxStock !== null &&
	data.minStock !== null &&
	parseInt(data.maxStock.toString()) < parseInt(data.minStock.toString())
	) {
	alert("min stock can't bigger than max value");
	return false;
	}
	if (isEmpty(data.maxPrice) != isEmpty(data.minPrice)) {
	alert('max and min price should both have values or both have no values at the same time');
	return false;
	}
	if (isEmpty(data.maxStock) != isEmpty(data.minStock)) {
	alert('max and min stock should both have values or both have no values at the same time');
	return false;
	}
	return true;
	};