Revert "Permission phase 2"

backend/src/lib/fn/array.ts

@@ -81,25 +81,3 @@ export const chunkArray = <T>(array: T[], chunkSize: number): T[][] => {
   }
   return chunks;
 };
-
-/*
- * Returns all items from the first list that
- * do not exist in the second list.
- */
-export const diff = <T>(
-  root: readonly T[],
-  other: readonly T[],
-  identity: (item: T) => string | number | symbol = (t: T) => t as unknown as string | number | symbol
-): T[] => {
-  if (!root?.length && !other?.length) return [];
-  if (root?.length === undefined) return [...other];
-  if (!other?.length) return [...root];
-  const bKeys = other.reduce(
-    (acc, item) => {
-      acc[identity(item)] = true;
-      return acc;
-    },
-    {} as Record<string | number | symbol, boolean>
-  );
-  return root.filter((a) => !bKeys[identity(a)]);
-};