ArabelaTso Metamorphic Test Generator
Overview
This skill generates test cases using metamorphic testing, applying transformations based on metamorphic properties to expand test suites and detect bugs through input-output relationships.
Quick Start
# Generate metamorphic tests
python scripts/generate.py program.py --tests tests/ --properties properties.json
# Use specific metamorphic properties
python scripts/generate.py program.py --tests tests/ --properties "permutation,addition"
# Generate report
python scripts/generate.py program.py --tests tests/ --properties props.json --output report.json
What Gets Generated
- Follow-up Test Cases - New inputs derived from original tests
- Property Verification - Checks that outputs satisfy metamorphic relations
- Violation Reports - Identifies property violations and anomalies
- Expanded Test Suite - Original plus generated tests
- Coverage Summary - Property coverage and effectiveness
Common Metamorphic Properties
- Permutation - Reordering inputs should not affect output
- Addition - Adding elements should increase/maintain result
- Multiplication - Scaling inputs should scale outputs proportionally
- Inverse - Applying inverse operation should return original
- Equivalence - Different representations should yield same result
- Monotonicity - Increasing input should increase/maintain output
Test Generation Report
Generates detailed report with:
- Original Tests - Initial test cases count
- Generated Tests - New test cases created
- Properties Applied - Metamorphic relations used
- Violations Found - Property violations detected
- Property Coverage - Percentage of properties satisfied
- Anomalies - Unexpected behaviors identified
Example report:
{
"original_tests": 20,
"generated_tests": 60,
"properties_applied": ["permutation", "addition", "inverse"],
"violations": 3,
"property_coverage": 95.0,
"anomalies": ["inverse property failed for negative inputs"]
}
Usage
python scripts/generate.py <program> --tests <test_dir> --properties <properties> [--output <report.json>]
Tips
- Define properties based on program semantics
- Start with simple properties (permutation, addition)
- Use metamorphic testing when oracles are unavailable
- Violations often indicate real bugs
- Combine with traditional testing for best results
- Document properties for future test maintenance