Metamorphic test generator

Skill ArabelaTso/Skills-4-SE/skills/metamorphic-test-generator

A curated list of 180+ useful Claude Skills for Software Engineering and resources for customizing AI for SE workflows.

Install

npx -y skills add ArabelaTso/Skills-4-SE --skill metamorphic-test-generator

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

What its author says it does

Copied from the file, not written here

Generate test cases using metamorphic testing by applying transformations based on metamorphic properties. Use when you need to expand test suites, test programs without oracles, validate mathematical or algorithmic properties, or detect subtle bugs through input-output relationships. The skill takes a program, original test cases, and metamorphic properties as input, generates new test cases by applying transformations, executes tests, verifies outputs satisfy properties, reports violations and anomalies, and outputs an expanded test suite with property coverage summary. Supports multiple programming languages and property types.

SKILL.md

3.1 KB, as published. Nobody here has run it

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