Code QuizAdvanced

Buggy Stub in Unit Test

Spot the mistake in a unit test that stubs a database dependency.

Codejavascript

// getUser fetches a user via the db dependency
function getUser(db, id) {
  return db.findById(id).name;
}

test('returns the user name from the db', () => {
  const dbStub = {
    findById: () => ({ name: 'Ada' })
  };

  const result = getUser(dbStub, 1);

  expect(result).toBe(dbStub);
});

What is the bug in this unit test?

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