test/parallel/test-timers-to-primitive.js

'use strict';

const common = require('../common');
const assert = require('assert');

[
  setTimeout(common.mustNotCall(), 1),
  setInterval(common.mustNotCall(), 1),
].forEach((timeout) => {
  assert.strictEqual(Number.isNaN(+timeout), false);
  assert.strictEqual(+timeout, timeout[Symbol.toPrimitive]());
  assert.strictEqual(`${timeout}`, timeout[Symbol.toPrimitive]().toString());
  assert.deepStrictEqual(Object.keys({ [timeout]: timeout }), [`${timeout}`]);
  clearTimeout(+timeout);
});

{
  // Check that clearTimeout works with number id.
  const timeout = setTimeout(common.mustNotCall(), 1);
  const id = +timeout;
  clearTimeout(id);
}

{
  // Check that clearTimeout works with string id.
  const timeout = setTimeout(common.mustNotCall(), 1);
  const id = `${timeout}`;
  clearTimeout(id);
}