How was the problem of code duplication in tests solved?

Several approaches are used to solve the problem of code duplication in tests:

• Extracting common functions and methods: repetitive actions are moved into separate helper functions or methods, which are then called from different tests.
• Using design patterns: for example, the Page Object pattern in UI tests helps encapsulate interaction with interface elements, reducing duplication.
• Test parameterization: allows running the same test with different input data, avoiding code copying.
• Configuring fixtures and setup/teardown methods: common preparation and cleanup of data are performed centrally.

An example in Python using pytest and parameterization:

import pytest

def add(a, b):
    return a + b

@pytest.mark.parametrize("a,b,expected", [
    (1, 2, 3),
    (5, 7, 12),
    (0, 0, 0),
])
def test_add(a, b, expected):
    assert add(a, b) == expected

This approach reduces the amount of repetitive code and makes test maintenance easier.