1/** Returns the last index of an item based on a given criteria. */ 2export function findLastIndex<T>(array: T[], predicate: (item: T) => boolean) { 3 for (let i = array.length - 1; i >= 0; i--) { 4 if (predicate(array[i])) { 5 return i; 6 } 7 } 8 return -1; 9} 10 11/** Returns a list of items that intersect between two given arrays. */ 12export function intersecting<T>(a: T[], b: T[]): T[] { 13 const [c, d] = a.length > b.length ? [a, b] : [b, a]; 14 return c.filter((value) => d.includes(value)); 15} 16 17export function replaceValue<T>(values: T[], original: T, replacement: T): T[] { 18 const index = values.indexOf(original); 19 if (index > -1) { 20 values[index] = replacement; 21 } 22 return values; 23} 24 25/** lodash.uniqBy */ 26export function uniqBy<T>(array: T[], key: (item: T) => string): T[] { 27 const seen: { [key: string]: boolean } = {}; 28 return array.filter((item) => { 29 const k = key(item); 30 if (seen[k]) { 31 return false; 32 } 33 seen[k] = true; 34 return true; 35 }); 36} 37 38/** `lodash.chunk` */ 39export function chunk<T>(array: T[], size: number): T[][] { 40 const chunked = []; 41 let index = 0; 42 while (index < array.length) { 43 chunked.push(array.slice(index, (index += size))); 44 } 45 return chunked; 46} 47