metamorphic-test-generator
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.
Install with Tessl CLI
npx tessl i github:ArabelaTso/Skills-4-SE --skill metamorphic-test-generator80
Does it follow best practices?
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npx tessl skill review --optimize ./path/to/skillValidation for skill structure
Discovery
85%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
This is a well-structured description that clearly explains what the skill does and when to use it. The main weakness is the reliance on technical jargon ('metamorphic testing', 'oracles') that users may not naturally use when requesting this functionality. The description is comprehensive but could benefit from more accessible trigger terms.
Suggestions
Add more natural trigger terms users might say, such as 'property-based testing', 'generate more tests', 'test coverage', or 'automated test generation'
Consider adding simpler synonyms alongside technical terms, e.g., 'test programs without oracles (expected outputs)' to improve discoverability
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: '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.' | 3 / 3 |
Completeness | Clearly answers both what (generate test cases using metamorphic testing, apply transformations, verify properties) AND when ('Use when you need to expand test suites, test programs without oracles, validate mathematical or algorithmic properties, or detect subtle bugs'). | 3 / 3 |
Trigger Term Quality | Includes some relevant terms like 'test cases', 'metamorphic testing', 'test suites', 'bugs', but 'metamorphic' is technical jargon most users wouldn't naturally say. Missing common variations like 'unit tests', 'testing', 'QA', or 'property-based testing'. | 2 / 3 |
Distinctiveness Conflict Risk | Very specific niche around metamorphic testing with distinct triggers like 'metamorphic properties', 'programs without oracles', and 'input-output relationships'. Unlikely to conflict with general testing or code generation skills. | 3 / 3 |
Total | 11 / 12 Passed |
Implementation
64%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This skill provides a clean, well-structured overview of metamorphic test generation with good CLI examples and output format. However, it lacks critical details like the properties.json schema, validation workflows for handling violations, and references to supporting documentation or scripts.
Suggestions
Add an example properties.json file showing how to define metamorphic properties with their transformations and expected relations
Include a workflow section with explicit steps for handling violations: interpret -> debug -> fix -> re-run -> verify
Clarify where scripts/generate.py comes from (is it provided? needs installation?) or link to the actual script location
Add a concrete example showing a simple program, its original test, the transformation applied, and how the property is verified
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The content is lean and efficient, avoiding unnecessary explanations of what metamorphic testing is or how it works conceptually. Every section provides actionable information without padding. | 3 / 3 |
Actionability | Provides concrete CLI commands and example output format, but lacks executable code showing how to define properties or integrate with actual programs. The properties.json format is never shown, making it incomplete for copy-paste usage. | 2 / 3 |
Workflow Clarity | The quick start shows a basic sequence but lacks validation checkpoints. No guidance on what to do when violations are found, how to interpret anomalies, or feedback loops for fixing issues and re-running tests. | 2 / 3 |
Progressive Disclosure | Content is well-organized with clear sections, but references scripts/generate.py without indicating where this script comes from or linking to additional documentation. No references to detailed property definition guides or advanced usage. | 2 / 3 |
Total | 9 / 12 Passed |
Validation
100%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 11 / 11 Passed
Validation for skill structure
No warnings or errors.
- Reviewed
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