toBeUndefined()

The toBeUndefined() method asserts that a value is exactly undefined.

Syntax

expect(actual).toBeUndefined();
expect(actual).not.toBeUndefined();

Returns

Type	Description
void	No return value

Description

The toBeUndefined() method checks if a value is exactly undefined. It only passes for the undefined value and fails for all other values, including null, false, 0, and empty strings.

Usage

import { expect } from 'https://jslib.k6.io/k6-testing/0.6.1/index.js';

export default function () {
  const user = {
    id: 123,
    name: 'John Doe',
    email: 'john@example.com',
  };

  // Check existing properties
  expect(user.id).not.toBeUndefined();
  expect(user.name).not.toBeUndefined();
  expect(user.email).not.toBeUndefined();

  // Check missing properties
  expect(user.phone).toBeUndefined();
  expect(user.address).toBeUndefined();

  // Basic undefined checks
  expect(undefined).toBeUndefined();
  expect(null).not.toBeUndefined();
  expect(false).not.toBeUndefined();
  expect(0).not.toBeUndefined();
}