core-js/tests/unit-pure/es.array.index-of.js

import { STRICT } from '../helpers/constants.js';

import indexOf from 'core-js-pure/es/array/index-of';

QUnit.test('Array#indexOf', assert => {
  assert.isFunction(indexOf);
  assert.same(indexOf([1, 1, 1], 1), 0);
  assert.same(indexOf([1, 2, 3], 1, 1), -1);
  assert.same(indexOf([1, 2, 3], 2, 1), 1);
  assert.same(indexOf([1, 2, 3], 2, -1), -1);
  assert.same(indexOf([1, 2, 3], 2, -2), 1);
  assert.same(indexOf([NaN], NaN), -1);
  assert.same(indexOf(Array(2).concat([1, 2, 3]), 2), 3);
  assert.same(indexOf(Array(1), undefined), -1);
  assert.same(indexOf([1], 1, -0), 0, "shouldn't return negative zero");
  if (STRICT) {
    assert.throws(() => indexOf(null, 0), TypeError);
    assert.throws(() => indexOf(undefined, 0), TypeError);
  }
});