Multi-Version Behavior Comparator
SkillDev toolsCompare behavior across multiple versions of programs or repositories. Use when you need to analyze how functionality changes between versions, identify regressions, compare outputs and exceptions, or validate upgrades. The skill compares execution behavior, test results, outputs, exceptions, and observable states across versions, generating detailed reports showing behavioral divergences, potential regressions, added/removed functionality, and areas requiring validation. Supports multiple programming languages and can work with test suites or execution traces.
Available today. Use it from your connected AI after setup.
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Connect ahel once, and every AI you use reads what you have installed.
Then ask your AI: use the Multi-Version Behavior Comparator skill
What this skill tells your AI
The instructions your AI receives, as published by arabelatso/skills-4-se in skills/multi-version-behavior-comparator/SKILL.md and read by ahel’s review.
Overview
This skill compares behavior across multiple versions of programs, identifying functional changes, regressions, and behavioral divergences to guide safe upgrades and validation.
Quick Start
# Compare two versions
python scripts/compare.py v1.0/ v2.0/
# Compare multiple versions with test suite
python scripts/compare.py v1.0/ v2.0/ v3.0/ --tests tests/
# Generate detailed report
python scripts/compare.py old/ new/ --output report.json
What Gets Compared
- Functionality - Added, removed, or modified features
- Outputs - Return values, printed output, file changes
- Exceptions - Error handling and exception types
- Test Results - Pass/fail status across versions
- Observable States - Side effects, state changes
Comparison Report
Generates JSON report with:
- Behavioral Divergences: Where versions behave differently
- Potential Regressions: Functionality that may have broken
- Added Features: New functionality in newer versions
- Removed Features: Functionality no longer present
- Validation Areas: Code requiring manual review
Usage
python scripts/compare.py <version1> <version2> [version3...] [--tests <test_dir>] [--output <report.json>]
Tips
- Run before deploying new versions
- Use with existing test suites for comprehensive comparison
- Review regressions carefully before upgrading
- Validate high-risk areas identified in report
Signals
- GitHub stars
- 252
- Forks
- 23
- Last commit
- Aug 2026
Advanced
- Catalog kind
- skill
- Gateway key
multi-version-behavior-comparator- Source
- github.com/arabelatso/skills-4-se