Test file and function naming conventions in PyTest - Build an Automation Script

Verify pytest recognizes test files and functions by naming conventions

Preconditions (2)

Step 1: Create a Python file named test_sample.py

Step 2: Inside test_sample.py, define a function named test_addition

Step 3: In test_addition, write an assertion that 2 + 2 equals 4

Step 4: Run pytest on the project folder

Step 5: Observe which tests pytest discovers and runs

✅ Expected Result: pytest discovers and runs the test_addition function inside test_sample.py and reports the test as passed

Automation Requirements - pytest

Assertions Needed:

Verify pytest discovers test files starting with 'test_'

Verify pytest discovers test functions starting with 'test_'

Verify the test function runs and passes

Best Practices:

Name test files starting with 'test_' and ending with '.py'

Name test functions starting with 'test_'

Use simple assert statements for validations

Keep test functions small and focused

Automated Solution

PyTest

import pytest

def test_addition():
    assert 2 + 2 == 4

# To run this test, save it in a file named test_sample.py
# Then run: pytest

# pytest will automatically discover this test because the file and function names start with 'test_'

The code defines a test function named test_addition inside a file named test_sample.py. This follows pytest's naming conventions.

pytest automatically finds files starting with test_ and functions starting with test_. The assertion checks a simple math operation.

When you run pytest, it discovers and runs this test, reporting success if the assertion passes.

Common Mistakes - 3 Pitfalls

{'mistake': "Naming test files without the 'test_' prefix, e.g., sample_test.py", 'why_bad': "pytest will not discover files that do not start with 'test_', so tests inside won't run.", 'correct_approach': "Always name test files starting with 'test_', like test_sample.py."}

{'mistake': "Naming test functions without the 'test_' prefix, e.g., addition_test()", 'why_bad': "pytest ignores functions that do not start with 'test_', so the test won't execute.", 'correct_approach': "Name test functions starting with 'test_', like test_addition()."}

Using print statements instead of assert for validations

Bonus Challenge

Now create three test functions in the same file to test addition, subtraction, and multiplication using correct naming conventions.

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