Function parsePageRange

src/scripts/stringUtils.ts:20–80

(text: string, maxRange?: number)

	 * corresponding to the numbers in that range. It ignores invalid input, sorts it, and removes duplicates
	 */
	export function parsePageRange(text: string, maxRange?: number): ParsedPageRange {
		if (ObjectUtils.isNullOrUndefined(text)) {
			return asFailedOperation("");
		}

		text = text.trim();

		if (text === "") {
			return asFailedOperation("");
		}

		let splitText = text.split(",");
		let range: number[] = [];

		for (let i = 0; i < splitText.length; ++i) {
			let valueToAppend: number[] = [], matches;
			let currentValue = splitText[i].trim();

			if (currentValue === "") {
				// We relax the restriction by allowing and ignoring whitespace between commas
				continue;
			}

			if (/^\d+$/.test(currentValue)) {
				let digit = parseInt(currentValue, 10 /* radix */);
				if (digit === 0 || !ObjectUtils.isNullOrUndefined(maxRange) && digit > maxRange) {
					return asFailedOperation(currentValue);
				}
				valueToAppend = [digit];
				// ... or it could a range of the form [#]-[#]
			} else if (matches = /^(\d+)\s*-\s*(\d+)$/.exec(currentValue)) {
				let lhs = parseInt(matches[1], 10), rhs = parseInt(matches[2], 10);
				// Try and catch an invalid range as soon as possible, before we compute the range
				// We also define a maxRangeAllowed as 2^32, which is the max size of an array in JS
				const maxRangeSizeAllowed = 4294967295;
				if (lhs >= rhs || lhs === 0 || rhs === 0 || lhs >= maxRangeSizeAllowed || rhs >= maxRangeSizeAllowed ||
					rhs - lhs + 1 > maxRangeSizeAllowed || (!ObjectUtils.isNullOrUndefined(maxRange) && rhs > maxRange)) {
					return asFailedOperation(currentValue);
				}
				valueToAppend = _.range(lhs, rhs + 1);
			} else {
				// The currentValue is not a single digit or a valid range
				return asFailedOperation(currentValue);
			}

			range = range.concat(valueToAppend);
		}

		let parsedPageRange = _(range).sortBy().sortedUniq().value();

		if (parsedPageRange.length === 0) {
			return asFailedOperation(text);
		}

		const last = _.last(parsedPageRange);
		if (!ObjectUtils.isNullOrUndefined(maxRange) && last > maxRange) {
			return asFailedOperation(last.toString());
		}