Have you had experience with unit testing and E2E testing?

Yes, I have experience with both unit testing and E2E testing. For unit tests, I use frameworks like Jest or Mocha, writing tests for individual components and functions to ensure logical correctness.

For E2E testing, I have used Cypress and Selenium to verify the application's overall functionality — from the user interface to server interactions.

Here's a simple example of a unit test in Jest:

function sum(a, b) {
  return a + b;
}

test('adds 1 + 2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3);
});

This approach helps quickly identify errors and maintain high code quality.