Installing and managing plugins in PyTest - Test Execution Walkthrough

Test Overview

This test checks if the pytest plugin pytest-cov is installed and working correctly by running a simple test and verifying the coverage report is generated.

Test Code - pytest

PyTest

import pytest

def test_sample():
    assert 1 + 1 == 2

# Run this test with coverage plugin enabled:
# pytest --cov=.

# The test verifies that the plugin runs and coverage data is collected.

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test runner starts pytest with the --cov plugin enabled	pytest initializes and loads installed plugins including pytest-cov	Check that pytest-cov plugin is loaded successfully	PASS
2	pytest discovers the test_sample function	Test file is parsed, test function found	Test function is recognized and ready to run	PASS
3	pytest runs test_sample	Test executes: assert 1 + 1 == 2	Assertion passes as 2 equals 2	PASS
4	pytest-cov collects coverage data during test run	Coverage plugin tracks executed lines	Coverage data is recorded without errors	PASS
5	pytest finishes and generates coverage report	Coverage report file is created in the project directory	Coverage report file exists and is not empty	PASS

Failure Scenario

Failing Condition: pytest-cov plugin is not installed or not enabled

Execution Trace Quiz - 3 Questions

What does the --cov option do when running pytest?

A Skips tests marked as slow

B Runs tests in verbose mode

C Enables the coverage plugin to track code coverage

D Generates HTML reports for test results

Key Result

Always verify that required plugins are installed and properly enabled before running tests that depend on them. Use plugin-specific command line options to confirm plugin functionality.