# Regression Check

> Plan regression checks for bug fixes, features, refactors, and release candidates. Use when Codex is asked to identify regression risk, define a regression test plan, verify a fix, choose smoke tests, or decide what must be retested after a code change.

- Skill: `gabrielmoreira/regression-check` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add gabrielmoreira/regression-check`
- Raw SKILL.md: https://api.skillmd.com/api/skills/gabrielmoreira/regression-check/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: MIT
- Author: gabrielmoreira (https://skillmd.com/u/gabrielmoreira)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/gabrielmoreira/regression-check

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# Regression Check

## Core Workflow

1. Identify the changed behavior, affected surfaces, dependencies, and user
   journeys.
2. Map the change to known invariants, prior bugs, adjacent workflows, and
   compatibility requirements.
3. Define targeted tests for the direct fix and broader regression tests for
   likely side effects.
4. Separate automated coverage from manual, exploratory, visual, accessibility,
   performance, or data checks.
5. Specify test data, environment, permissions, feature flags, and observability
   needed for verification.
6. State residual risk and release gate recommendation.

## Safety Rules

- Do not treat tests as passed unless output or evidence is available.
- Do not rely only on happy-path checks for auth, billing, data, migrations, or
  customer-facing workflows.
- Escalate when there is no reproducible baseline, missing test data, unclear
  owner, or high-risk production dependency.

## Deliverable Shape

For regression work, provide:

- Changed surface
- Regression risk areas
- Direct verification tests
- Broader regression tests
- Automation versus manual coverage
- Test data and environment needs
- Release gate recommendation
- Residual risk

## References

- Read `references/regression-check-checklist.md` when planning or reviewing
  regression coverage.