characterization-test-generator
Generate characterization tests to capture and verify existing behavior before migration
npx skills add a5c-ai/babysitter --skill characterization-test-generator --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Characterization Test Generator Skill Generates characterization tests (also known as golden master tests or approval tests) to capture existing system behavior before migration, ensuring functional equivalence after changes. ## Purpose Enable behavior preservation during migration through: - Golden master test creation - Approval test generation - Edge case discovery - Input/output recording - Behavior snapshot capture - Regression baseline establishment ## Capabilities ### 1. Golden Master Test Creation - Capture current system outputs for given inputs - Store outputs as reference "golden" files - Generate comparison test infrastructure - Support multiple output formats - Enable baseline versioning ### 2. Approval Test Generation - Create human-reviewable test outputs - Generate diff-based comparison tests - Support approval workflows - Enable incremental approval - Track approval history ### 3. Edge Case Discovery - Analyze code paths for boundary conditions - Generate boundary value inputs - Identify error handling scenarios - Map exception paths - Create comprehensive test coverage ### 4. Input/Output Recording - Instrument code for I/O capture - Record API request/response
- Purpose
- Capabilities
- 1. Golden Master Test Creation
- 2. Approval Test Generation
- 3. Edge Case Discovery
- 4. Input/Output Recording
- 5. Behavior Snapshot
- 6. Regression Baseline Establishment
- Tool Integrations
- Usage
- Basic Test Generation
- Generation Workflow
- Output Schema
- Integration with Migration Processes
Invoke skill for characterization test generation The skill will analyze code and generate tests Expected inputs:
What does the characterization-test-generator skill do?
Generate characterization tests to capture and verify existing behavior before migration
How do I install it?
Run `npx skills add a5c-ai/babysitter --skill characterization-test-generator --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From a5c-ai/babysitter, a repository with 1,642 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.