Integration Test

ELI5 — The Vibe Check

If a unit test checks one LEGO brick, an integration test checks that two bricks actually snap together correctly. You test how different parts of your code talk to each other — like making sure your login button actually talks to your database.

Real Talk

Integration tests verify that multiple components or systems work correctly together. Unlike unit tests, they don't mock dependencies — they test real interactions between modules, services, databases, or APIs.

Show Me The Code

test('user can log in and fetch profile', async () => {
  const token = await loginUser('test@example.com', 'password');
  const profile = await getProfile(token);
  expect(profile.email).toBe('test@example.com');
});

When You'll Hear This

"Integration tests caught that the API wasn't returning the right shape." / "Run the integration tests before merging."