feat: add intersection, union, complement, fullIntersection, array utility methods

src/modules/esl-utils/misc/array.ts

@@ -29,13 +29,34 @@ export const uniq = <T> (arr: T[]): T[] => {
   return result;
 };
 
-/** Crete an array filled with the range [0,..,N-1] */
+/** Create an array filled with the range [0,..,N-1] */
 export function range(n: number): number[];
-/** Crete an array filled with values returned by the filler callback */
+/** Create an array filled with values returned by the filler callback */
 export function range<T>(n: number, filler: (i: number) => T): T[];
 export function range(n: number, filler: (i: number) => any = identity): any[] {
   const arr = Array(n);
   let i = 0;
   while (i < n) arr[i] = filler(i++);
   return arr;
 }
+
+/** Create an array of unique values from two arrays*/
+export function intersection(a: any, b: any): any[] {
+  const arr = new Set([...a, ...b]);
+  return [...arr];
+}
+
+/** Create an array from two arrays*/
+export function union(a: any, b: any): any[] {
+  return [...a, ...b];
+}
+
+/** Creates an array of unique values from the first array that are not present in the second array*/
+export function complement(a: any, b: any): any[] {
+  return a.filter((item: any) => !b.includes(item));
+}
+
+/** Check for elements from array B in array A*/
+export function fullIntersection(a: any, b: any): boolean {
+  return a.length === 0 && b.length === 0 ? true : !b.filter((item: any) => !a.includes(item)).length;
+}

src/modules/esl-utils/misc/test/array.test.ts

@@ -1,4 +1,4 @@
-import {flat, range, tuple, uniq, wrap} from '../array';
+import {flat, range, tuple, uniq, wrap, intersection, union, complement, fullIntersection} from '../array';
 
 describe('misc/array helper tests', () => {
   test('tuple', () => {
@@ -45,3 +45,39 @@ describe('misc/array helper tests', () => {
     expect(range(9, (x) => x / 8)).toEqual([...Array(9).keys()].map((x) => x / 8))
   });
 });
+
+test('intersection', () => {
+  const a = {a:3};
+  expect(intersection([],[])).toEqual([]);
+  expect(intersection([1],[1])).toEqual([1]);
+  expect(intersection([1, 2], [1, 2])).toEqual([1, 2]);
+  expect(intersection([1, [2, 3], a], [a, 1, [2, 3]])).toEqual([1, [2, 3], a, [2, 3]]);
+  expect(intersection([null, 1, 2, 3, null, [6]], [4, 5])).toEqual([null, 1, 2, 3, [6], 4, 5, ]);
+});
+
+test('union', () => {
+  const a = {a:3};
+  expect(union([],[])).toEqual([]);
+  expect(union([1],[1])).toEqual([1, 1]);
+  expect(union([1, 2], [1, 2])).toEqual([1, 2, 1, 2]);
+  expect(union([1, [2, 3], a], [a, 1, [2, 3]])).toEqual([1, [2, 3], a, a, 1, [2, 3]]);
+  expect(union([null, 1, 2, 3, null, [6]], [4, 5])).toEqual([null, 1, 2, 3, null, [6], 4, 5, ]);
+});
+
+test('complement', () => {
+  const a = {a: 3};
+  expect(complement([],[])).toEqual([]);
+  expect(complement([1],[1])).toEqual([]);
+  expect(complement([1, 2, 3], [1, 2])).toEqual([3]);
+  expect(complement([1, [2, 3], a], [a, 1, [2, 3]])).toEqual([[2, 3]]);
+  expect(complement([null, 1, 2, 3, null, [6]], [4, 5])).toEqual([null, 1, 2, 3, null, [6]]);
+});
+
+test('fullIntersection', () => {
+  const a = {a: 3};
+  expect(fullIntersection([],[])).toEqual(true);
+  expect(fullIntersection([1],[1])).toEqual(true);
+  expect(fullIntersection([1, 2, 3], [1, 2])).toEqual(true);
+  expect(fullIntersection([1, [2, 3], a], [a, 1, [2, 3]])).toEqual(false);
+  expect(fullIntersection([null, 1, 2, 3, null, [6]], [4, 5])).toEqual(false);
+});