count-spec.ts

import '../iterablehelpers';
import { count } from 'ix/iterable/index.js';

test('Iterable#count no predicate empty', () => {
  expect(count<number>([])).toBe(0);
});

test('Iterable#count no predicate non-empty', () => {
  expect(count([1, 2, 3])).toBe(3);
});

test('Iterable#count predicate empty', () => {
  expect(
    count<number>([], { predicate: (x) => x < 3 })
  ).toBe(0);
});

test('Iterable#count predicate some', () => {
  expect(count([1, 2, 3], { predicate: (x) => x < 3 })).toBe(2);
});