Unit Testing: Are You Chasing Coverage or Quality? ??

As developers, we often hear "Ensure 90%+ test coverage!" But does high coverage mean good tests? Not always.

?? What Unit Testing Should Do: ? Catch edge cases (invalid inputs, boundary conditions) ? Validate business logic under different scenarios ? Ensure fast, isolated tests without external dependencies ? Use mocks where needed

? What Unit Testing Should NOT Be: ? Writing tests just to increase coverage % ? Ignoring real-world edge cases ? Skipping validation of invalid inputs

?? Bad Unit Test (Just for Coverage) Covers function execution but misses real-world scenarios:

def add_numbers(a, b):  
    return a + b  # Simple function

# Unit Test
def test_add():
    assert add_numbers(2, 3) == 5  # ? Covers code, ? but not all cases
        

?? Good Unit Test (Covers Edge Cases)

import pytest

def test_add_numbers():
    assert add_numbers(2, 3) == 5  
    assert add_numbers(-2, -3) == -5  
    assert add_numbers(-2, 3) == 1  
    assert add_numbers(2.5, 3.1) == 5.6  

    with pytest.raises(ValueError):
        add_numbers("2", 3)  # ? Invalid input should raise error
        

? Better Coverage ? Stronger Tests ? Confident Codebase

?? Bottom Line: Aim for quality testing, not just coverage. What’s your take on unit testing? Let’s discuss! ????

#SoftwareDevelopment #SoftwareTesting #UnitTesting #QualityCode #DeveloperLife #Python