regression-check - SKILL.md Agent Skill

name: regression-check description: Review code changes for functional correctness and regressions in Zowe Explorer. Focuses on tree view actions, filesystem APIs, and extension initialization. Use when validating a completed feature, bug fix, or refactor before merging or release.

QA Regression Check

Use this skill to validate a completed or nearly completed feature, bug fix, or refactor for correctness, regressions, and release readiness in the Zowe Explorer monorepo.

Gotchas

Direct filesystem access: fs or path node module calls for mainframe resources will break. Always verify the use of Zowe filesystem providers or vscode.workspace.fs.
Silent UI Failures: Unhandled promises in Actions classes (e.g., MvsActions, UssActions) might fail silently. Ensure actions use AuthUtils.errorHandling and display appropriate messages via Gui, or implement essential error handling for scenarios that AuthUtils.errorHandling does not cover.
Extension API Contract: Modifying method signatures or expected arguments in zowe-explorer-api can break dependent extensions without failing local tests.
Activation Crashes: A failure or unhandled exception during extension initialization or initForZowe() will prevent the entire extension from activating.

Validation Workflow

Follow this explicit checklist when auditing changes:

Step 1: Extension Initialization
- Verify the extension activates successfully without crashes in the debug console or log output.
- Ensure activate() and initForZowe() complete without unhandled errors.
Step 2: Tree View Actions
- Verify context menu actions (e.g., copy, paste, delete, rename, upload) function correctly on affected tree nodes.
- Check that tree view state refreshes appropriately after modifications.
Step 3: Filesystem APIs
- Check operations like readFile, writeFile, and directory listings for stability.
- Verify edge cases like 412 conflicts or unsafe uploads are handled gracefully.
Step 4: Edge Cases & Error Handling
- Ensure AuthUtils.errorHandling is used consistently to catch and log errors.
- Check that missing data (e.g., missing hostnames in profiles) triggers fallback flows like openConfigForMissingHostname.
Step 5: Happy Path & Core Functionality
- Verify the primary flow behaves as requested without obvious blocking issues.

Output Template

Return the validation results using this exact markdown template:

### QA Summary

[Short summary of overall status and regression risk]

### Issues Found

- **[Issue Title]**
  - **Expected:** [What should happen]
  - **Actual:** [What happened]
  - **Severity:** [Critical | High | Medium | Low]
  - **Affected Area:** [e.g., Tree View, Filesystem, Activation]
  - **Reproduction:** [Simple steps to reproduce]

_(Omit "Issues Found" if none exist)_

### Regression Risk Notes

[Call out any areas that need follow-up checks or mention potential impact on extenders]

### Acceptance Checklist

- [ ] All reported issues addressed
- [ ] Required tests pass (e.g., `pnpm test`, `pnpm test:e2e`)

Rules

Do not claim something was tested if it was not actually checked or verified with evidence.
Do not silently change scope during QA.
Do not assume extension activation succeeds without checking log output.
Do not overlook unhandled promises or silent failures in UI commands.