import subprocess
import sys
import re
import pytest
def test_pytest_cov_plugin_installation_and_usage():
# Step 1: Install pytest-cov plugin
install_result = subprocess.run([sys.executable, '-m', 'pip', 'install', 'pytest-cov'], capture_output=True, text=True)
assert install_result.returncode == 0, f"Failed to install pytest-cov: {install_result.stderr}"
# Step 2: Create a simple test file
test_code = '''def test_always_passes():
assert True
'''
with open('test_sample.py', 'w') as f:
f.write(test_code)
# Step 3: Run pytest with coverage
run_result = subprocess.run([sys.executable, '-m', 'pytest', '--cov=test_sample.py', 'test_sample.py'], capture_output=True, text=True)
output = run_result.stdout + run_result.stderr
# Step 4: Assertions
# Check pytest-cov plugin is mentioned in output
assert 'pytest-cov' in output or 'coverage' in output, "pytest-cov plugin output not found"
# Check tests passed
assert '1 passed' in output, "Test did not pass as expected"
# Check coverage report summary presence
coverage_pattern = re.compile(r'TOTAL\s+\d+\s+\d+\s+\d+%')
assert coverage_pattern.search(output), "Coverage summary not found in output"
# Cleanup test file
import os
os.remove('test_sample.py')
if __name__ == '__main__':
pytest.main([__file__])This test script automates the manual test case steps.
First, it installs the pytest-cov plugin using pip via subprocess.run. It asserts the installation succeeded by checking the return code.
Next, it creates a simple test file test_sample.py with one passing test function.
Then, it runs pytest with coverage enabled on that test file, capturing the output.
Assertions check that the plugin output is present, the test passed, and the coverage summary is shown.
Finally, it cleans up the test file to keep the environment clean.
This approach uses subprocess calls to simulate real user commands and verifies outputs, following best practices for plugin management testing.
