What are isolated unit tests and why are they important?

What are isolated unit tests and why are they important?

Isolated unit tests are tests that focus on a single component or function in isolation from the rest of the system. They are important because they help ensure that each part of the code works correctly on its own, making it easier to identify bugs and maintain the codebase.

How do I write an isolated unit test?

To write an isolated unit test, you should use a testing framework like JUnit or pytest. Start by creating a test case that sets up the necessary environment, then call the function you want to test with specific inputs, and finally assert that the output matches your expectations.

What are some common mistakes to avoid when writing these tests?

Common mistakes include not isolating the unit properly, relying on external systems, and not covering edge cases. It's crucial to ensure that your tests are truly isolated to get accurate results.

Can you give me an example of an isolated unit test?

Sure! Here's a simple example in Python using pytest:

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

def test_add():
    assert add(2, 3) == 5
    assert add(-1, 1) == 0

This tests the add function in isolation.