Function smartGrouping

lib/util/smartGrouping.js:63–227

(items, groupConfigs)

 * @returns {(I | G)[]} grouped items
 */
const smartGrouping = (items, groupConfigs) => {
	/** @type {Items<I, G>} */
	const itemsWithGroups = new Set();
	/** @type {Map<string, Group<I, G>>} */
	const allGroups = new Map();
	for (const item of items) {
		/** @type {Groups<I, G>} */
		const groups = new Set();
		for (let i = 0; i < groupConfigs.length; i++) {
			const groupConfig = groupConfigs[i];
			const keys = groupConfig.getKeys(item);
			if (keys) {
				for (const name of keys) {
					const key = `${i}:${name}`;
					let group = allGroups.get(key);
					if (group === undefined) {
						allGroups.set(
							key,
							(group = {
								config: groupConfig,
								name,
								alreadyGrouped: false,
								items: undefined
							})
						);
					}
					groups.add(group);
				}
			}
		}
		itemsWithGroups.add({
			item,
			groups
		});
	}

	/**
	 * Returns groups items.
	 * @param {Items<I, G>} itemsWithGroups input items with groups
	 * @returns {(I | G)[]} groups items
	 */
	const runGrouping = (itemsWithGroups) => {
		const totalSize = itemsWithGroups.size;
		for (const entry of itemsWithGroups) {
			for (const group of entry.groups) {
				if (group.alreadyGrouped) continue;
				const items = group.items;
				if (items === undefined) {
					group.items = new Set([entry]);
				} else {
					items.add(entry);
				}
			}
		}
		/** @type {Map<Group<I, G>, { items: Items<I, G>, options: GroupOptions | false | undefined, used: boolean }>} */
		const groupMap = new Map();
		for (const group of allGroups.values()) {
			if (group.items) {