User Interaction Testing

Problem

Tests that directly manipulate component state miss bugs that users encounter. Event handlers break, form submissions fail, or click interactions don’t trigger the expected behavior because tests bypass the actual DOM event system that users interact with.

Solution

Simulate clicks, typing, and other user events in tests to verify components respond correctly. This tests behavior from the user’s perspective.

Example

This demonstrates testing components by simulating user interactions like clicks and typing, verifying components respond correctly from the user’s perspective rather than testing implementation details.

test('clicking button updates count', () => {
  render(<Counter />);

  // Query by role - how screen readers and users find elements
  const button = screen.getByRole('button', { name: /increment/i });
  // Simulate real user click event
  fireEvent.click(button);

  // Verify UI updated correctly
  expect(screen.getByText('Count: 1')).toBeInTheDocument();
});

Benefits

• Tests components the way users actually interact with them.
• Catches bugs in event handlers that state manipulation tests miss.
• Provides confidence that features work in real browsers.
• Tests accessibility by verifying keyboard and screen reader interactions work.

Tradeoffs

• Slower than unit tests since they involve DOM rendering and events.
• Can be flaky if timing or async behavior isn’t properly handled.
• May not catch issues that only appear in specific browsers.
• Requires understanding event simulation APIs and testing library patterns.