---
name: regression-check
description: Run a comprehensive health check across the monorepo after completing a phase or major change
type: review
version: v0.0
argument-hint: "[optional: specific package or directory to focus on]"
---

# Regression Check

Run a comprehensive health check across the project or monorepo to catch regressions, broken imports, type errors, and lint failures after completing a phase or major change.

## Process

1. **Determine scope:**
   - If `$ARGUMENTS` specifies a package or directory, focus there but still check dependents.
   - Otherwise, check the entire project.
   - Read `CLAUDE.md` for project conventions and available commands.

2. **Type checking:**
   - Run `tsc --noEmit` (or the project's type-check command from `package.json`).
   - Collect and categorize errors by package/directory.

3. **Lint check:**
   - Run the project's lint command (from `package.json` scripts).
   - Collect errors (ignore warnings unless they indicate real issues).

4. **Test suite:**
   - Run the full test suite (or scoped if `$ARGUMENTS` provided).
   - Collect failures with file paths and error messages.
   - Note any tests that were skipped or marked as TODO.

5. **Build check:**
   - Run the build command to verify the project compiles.
   - Catch issues that type-checking alone misses (e.g., missing assets, broken dynamic imports).

6. **Import health:**
   - Check for circular dependencies if a tool is available (`madge`, `dpdm`, or manual detection).
   - Verify that all import paths resolve (no broken imports from moved/deleted files).

7. **Environment check:**
   - Verify `.env.example` (or equivalent) matches the env vars actually used in code.
   - Flag any new env vars added without documentation.

8. **Compare with baseline:**
   - If there's a CI status or previous test run to compare against, note new failures vs. pre-existing ones.

## Output Format

### Health Check Results

| Check | Status | Details |
|-------|--------|---------|
| Type check | pass/fail | X errors in Y files |
| Lint | pass/fail | X errors |
| Tests | pass/fail | X passed, Y failed, Z skipped |
| Build | pass/fail | error details if failed |
| Imports | pass/fail | circular deps or broken imports |
| Env vars | pass/fail | missing documentation |

### Failures (if any)

#### Type Errors
- `file.ts:42` — error description

#### Test Failures
- `test-file.test.ts` — test name — error

#### Build Errors
- error details

### Regressions vs. Pre-existing
- **New failures**: list (introduced by recent changes)
- **Pre-existing**: list (existed before this phase)

### Verdict
- **All clear**: safe to ship
- **Issues found**: list what needs fixing before shipping

## Follow-Through

After presenting the health check results, if the verdict is "Issues found":

1. Read `tasks/todo.md` if it exists — append actionable failures to the end under a `## Regression Fixes` heading (create the file if it doesn't exist). Write non-blocking future validations or unavailable-data checks to `tasks/record-todo.md` instead.
2. Add one checkbox item per **new** failure (not pre-existing), grouped by check type:
   ```markdown
   ## Regression Fixes
   > Generated by `/regression-check` on [date]
   - [ ] **Type error**: `file.ts:42` — error description
   - [ ] **Test failure**: `test-file.test.ts` — test name — error
   - [ ] **Build error**: error details
   - [ ] **Broken import**: `file.ts` — import path that doesn't resolve
   ```
3. Do **not** add pre-existing issues — only new regressions introduced by recent changes.
4. If `tasks/todo.md` already has a `## Regression Fixes` section, replace it with the fresh results.
5. If the verdict is "All clear", do not write anything to todo — just confirm the clean bill of health.
6. Tell the user how many items were added and suggest `/investigate` or `/run` to start fixing.

## Constraints
- Run checks in parallel where possible (type-check and lint can run simultaneously).
- Clearly distinguish between new regressions and pre-existing issues.
- Do not fix issues automatically — only report them and write todo items. The user decides what to fix.
- If a check command doesn't exist in the project, skip it and note that it's unavailable.
- Keep the output actionable — every failure should have a file path and enough context to fix it.


## Alignment Page

When this skill produces durable deliverables (research, specs, plans, reports, prototypes, or any document output), build a full-depth HTML alignment page at `alignment/regression-check-{topic}.html`. Use a normalized topic slug derived from the app, feature, research subject, report subject, or output filename.

**Full content requirement.** The alignment page must contain the complete content of every proposed markdown deliverable -- every section, every finding, every detail, every list item. It is a thorough interactive review document, not a summary. Render the full deliverable content in clean, readable HTML with appropriate hierarchy, styling, and navigation. If the skill writes multiple scoped deliverables in one run, build one alignment page that contains all deliverables with anchor-linked navigation. Durable tracker artifacts, such as `research/assumption-tracker.md`, remain canonical markdown outputs but must also be fully rendered into the alignment page before approval.

**Dark-mode styling.** Use a dark color scheme by default. Base CSS variables: `--bg: #0d1117; --surface: #161b22; --border: #30363d; --text: #c9d1d9; --text-muted: #8b949e; --accent: #58a6ff; --green: #3fb950; --red: #f85149; --orange: #d29922; --purple: #bc8cff;`. Apply `background: var(--bg); color: var(--text);` on body. Use `--surface` for cards, nav, and table headers. Use `--border` for all borders. Use `--purple` for question blocks and gate headings. Use `--accent` for links and section headings. Keep headings `color: #fff` or `var(--accent)` for hierarchy. Question block backgrounds should use `#1c2333`.

**Alignment gates.** Treat gates as explicit review sections inside the HTML page. A gate blocks finalization until its required inline questions are answered and compiled into YAML. Include every gate that applies to the skill output, and include these gate types whenever relevant: evidence coverage, assumptions/confidence, scope/non-goals, candidate/verdict decisions, artifact destination, proposed file changes, coverage checkpoint, and post-approval route.

**Report-only research gates.** For report-only or pre-approval research skills, the alignment page must explicitly contain evidence coverage, assumptions/confidence, recommended path, proposed file changes, and approval gates before any canonical research, spec, or task file is created or updated.


**Required inline questions.** Each gate must contain at least one required inline question placed directly under the content it governs, inside a visually distinct question block. Each question must use radio-button inputs and include two standing options after the skill-generated choices: "Other / None of the above" backed by a multi-line text box for free-form input, and "Need clarification" backed by an optional notes box where the user can explain what is unclear. When any radio option other than "Other" or "Need clarification" is selected, show an optional "Additional notes" text box beneath it so the user can qualify their choice. Generate questions based on what genuinely needs user input -- do not add filler questions. Do not create a separate bottom "Decisions & Clarifications" section.

**Gate YAML contract.** At the bottom of the page, include a "Compile Answers" button that aggregates answers from all inline gate questions throughout the page, including free-text notes. The button remains disabled until every required question has a selection, shows a count of remaining unanswered questions, and scrolls to the first unanswered question if clicked early. When every question is answered, generate a structured YAML block with one item per gate answer using this stable shape: `section`, `gate_type`, `status` (`answered`, `other`, or `needs-clarification`), `answer`, optional `notes`, and optional `target_artifact` or `target_path` when the gate controls file output. After successful compilation, automatically attempt to copy the YAML to the clipboard with the Clipboard API, display copy status, and display the YAML in a read-only textarea with an explicit "Copy YAML" button. The copy button must retry clipboard copy when supported and fall back to selecting the textarea contents when clipboard access is unavailable or blocked.

**Pre-approval stop.** Before user approval, the next action is review of the HTML alignment page, not downstream routing. Ask the user to review the page and provide the compiled YAML answers. Do not include `Recommended next skill`, `Recommended next command`, or downstream routing language until after compiled YAML has been provided and the approved artifacts have been written or updated.

**Diff highlighting on updates.** When the agent updates an existing alignment page after receiving compiled answers, highlight what changed since the previous version. The agent chooses inline annotation or side-by-side layout per situation.

**Archiving.** Before replacing an existing alignment page, archive it to `docs/history/archive/YYYY-MM-DD/HHMMSS/alignment/regression-check-{topic}.html`.

**Browser open.** Attempt to open the resulting HTML page in the browser and report whether the open succeeded or was blocked. A blocked browser-open attempt does not make the skill fail when the files were written correctly.

## Default Shipping Contract

- **Default next-step routing:** when reporting completion, include either `Recommended next skill: <command>` or the two-line pair `**Next work:** <specific task or "none">` and `**Recommended next command:** <one command or route>` so the next operator has a concrete handoff.
- If this skill creates or modifies tracked repository files, finish by committing and pushing all intended changes to the repository primary branch (`main` when present, otherwise `master`) before stopping, even if the user did not explicitly ask for commit/push.
- Do not leave tracked changes or unpushed commits behind. If unrelated tracked work is already present, either include it in sensible commits too or stop and explain the blocker.
- This contract does not override stricter safety rules about secrets, destructive history changes, release publication/tag confirmation, or production deploy confirmation.
