feat: allow sorted-lists on multiple pages

If multiple sorted-lists were on separate pages, saving one page would erase the sorted-lists saved on the other page. This was caused by naive deletion of the sorted-lists index on settings save.

At the same time, a bug was found where if fewer items were passed in, only that many items were removed from the database, leaving leftover orphan data in the database.

The logic now:

- Only removes sorted-lists if they are passed in (and empty)
- Deletes all sorted list items, not just the items passed in.

src/meta/settings.js

@@ -58,14 +58,18 @@ Settings.set = async function (hash, values, quiet) {
 	const sortedLists = Object.keys(sortedListData);
 
 	if (sortedLists.length) {
-		await db.delete('settings:' + hash + ':sorted-lists');
 		await db.setAdd('settings:' + hash + ':sorted-lists', sortedLists);
 
+		// Remove provided (but empty) sorted lists from the hash set
+		await db.setRemove('settings:' + hash + ':sorted-lists', sortedLists.filter(list => !sortedListData[list].length));
+
 		await Promise.all(sortedLists.map(async function (list) {
-			await db.delete('settings:' + hash + ':sorted-list:' + list);
-			await Promise.all(sortedListData[list].map(async function (data, order) {
-				await db.delete('settings:' + hash + ':sorted-list:' + list + ':' + order);
-			}));
+			const numItems = await db.sortedSetCard('settings:' + hash + ':sorted-list:' + list);
+			const deleteKeys = ['settings:' + hash + ':sorted-list:' + list];
+			for (let x = 0; x < numItems; x++) {
+				deleteKeys.push('settings:' + hash + ':sorted-list:' + list + ':' + x);
+			}
+			await db.deleteAll(deleteKeys);
 		}));
 
 		const ops = [];