Defect classification (severity, priority) in Testing Fundamentals - Build an Automation Script

Classify defects by severity and priority

Preconditions (2)

Step 1: Review each defect description

Step 2: Assign a severity level: Critical, Major, Minor, or Trivial

Step 3: Assign a priority level: High, Medium, or Low

Step 4: Verify that severity and priority are assigned correctly according to rules

Step 5: Rules: Critical severity means High priority, Minor severity means Low priority, Major severity usually Medium priority

✅ Expected Result: Each defect is correctly classified with severity and priority matching the rules

Automation Requirements - pytest

Assertions Needed:

Assert severity is one of ['Critical', 'Major', 'Minor', 'Trivial']

Assert priority is one of ['High', 'Medium', 'Low']

Assert priority matches severity rules

Best Practices:

Use parameterized tests for multiple defects

Use clear assertion messages

Keep classification logic separate from test code

Automated Solution

Testing Fundamentals

import pytest

# Function to classify priority based on severity

def classify_priority(severity: str) -> str:
    severity = severity.lower()
    if severity == 'critical':
        return 'High'
    elif severity == 'major':
        return 'Medium'
    elif severity == 'minor':
        return 'Low'
    elif severity == 'trivial':
        return 'Low'
    else:
        raise ValueError(f"Unknown severity level: {severity}")

# Sample defects data
sample_defects = [
    {'id': 1, 'description': 'App crashes on launch', 'severity': 'Critical', 'priority': 'High'},
    {'id': 2, 'description': 'UI alignment issue', 'severity': 'Minor', 'priority': 'Low'},
    {'id': 3, 'description': 'Slow response time', 'severity': 'Major', 'priority': 'Medium'},
    {'id': 4, 'description': 'Typo in help text', 'severity': 'Trivial', 'priority': 'Low'}
]

@pytest.mark.parametrize('defect', sample_defects)
def test_defect_classification(defect):
    severity = defect['severity']
    priority = defect['priority']

    # Check severity is valid
    assert severity in ['Critical', 'Major', 'Minor', 'Trivial'], \
        f"Severity '{severity}' is not valid"

    # Check priority is valid
    assert priority in ['High', 'Medium', 'Low'], \
        f"Priority '{priority}' is not valid"

    # Check priority matches severity rules
    expected_priority = classify_priority(severity)
    assert priority == expected_priority, \
        f"Priority '{priority}' does not match expected '{expected_priority}' for severity '{severity}'"

This test script uses pytest to automate defect classification verification.

The classify_priority function defines the expected priority for each severity level. This keeps logic separate and clear.

The sample_defects list contains example defects with their severity and priority.

The test test_defect_classification runs for each defect using pytest.mark.parametrize. It asserts that severity and priority values are valid and that priority matches the expected value based on severity.

This approach is simple, clear, and easy to extend with more defects.

Common Mistakes - 3 Pitfalls

Hardcoding priority values in test without using a classification function

Not validating severity and priority values before assertions

Using print statements instead of assertions for verification

Bonus Challenge

Now add data-driven testing with 3 different defect inputs including edge cases

Show Hint