# Review: Informative Slack Pipeline Notifications — Round 3

**Reviewer:** Linus Torvalds
**Branch:** `colonyos/when_you_output_followups_in_the_thread_on_slack_a938599349`
**PRD:** `cOS_prds/20260331_190640_prd_you_are_a_code_assistant_working_on_behalf_of_the_engineering_team_the_following.md`
**Tests:** 135 pass (test_slack_formatting.py + test_sanitize.py)
**Commits:** 10 commits, +1,333 / -23 lines

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## Checklist

### Completeness
- [x] FR-1: Task completion messages include description — `phase_header` now shows `Implement [1.0] Frontend dependencies...`
- [x] FR-2: Task outline uses bullet formatting — `_format_task_outline_note()` emits `•` bullets with newlines, bold header
- [x] FR-3: Task result summary includes descriptions — `_format_implement_result_note()` renders categorized bullet lists with cost/duration
- [x] FR-4: Review round messages include finding summaries — `_extract_review_findings_summary()` with 3-tier fallback, findings shown per reviewer
- [x] FR-5: Sanitization — double-layer `sanitize_untrusted_content()` → `sanitize_for_slack()` applied at all 7 ingress points
- [x] Zero new LLM calls
- [x] 3,000-char message cap via `_truncate_slack_message()`

### Quality
- [x] All 135 tests pass
- [x] Code follows existing project conventions
- [x] No unnecessary dependencies added
- [x] No unrelated changes included
- [x] Named constants extracted (`_SLACK_MAX_CHARS`, `_SLACK_MAX_SHOWN_TASKS`, `_SLACK_TASK_DESC_MAX`, `_SLACK_FINDING_MAX`)

### Safety
- [x] No secrets or credentials in committed code
- [x] Mention injection neutralized (case-insensitive, covers `@here/@channel/@everyone`, `<!here>`, `<@U...>`, `<@B...>`, `<@W...>`)
- [x] Link injection neutralized (arbitrary URI schemes with display text, bare links for http/https/mailto/slack protocols)
- [x] mrkdwn metacharacters escaped
- [x] Truncation caps prevent information leakage

---

## Findings

None blocking.

The previous rounds' non-blocking findings have all been addressed in commit `7def16c`:
- Phase header truncation now uses `_SLACK_TASK_DESC_MAX` instead of hardcoded `60`/`57` — good, use the damn constant everywhere
- `_SLACK_BARE_LINK_RE` expanded to cover `mailto:` and arbitrary `scheme://` URIs — closes the asymmetry with `_SLACK_LINK_INJECTION_RE`
- DEBUG audit logging added to `sanitize_for_slack()` when content is neutralized — costs nothing, aids debugging

The one thing I noted in round 2 that's still present:

- **[src/colonyos/orchestrator.py]**: `_extract_review_findings_summary` — the blank-line handling in the FINDINGS parser (`continue` on empty lines) means a review with blank lines between findings followed by non-`-` prose will keep collecting past the blank lines until it hits a non-blank non-finding line. The state machine is slightly loose. But the review template doesn't produce this pattern in practice, and the `max_findings` cap limits the damage. Not worth complicating the parser for a theoretical edge case.

- **[src/colonyos/orchestrator.py]**: `_format_task_list_with_descriptions` silently swallows `ValueError`/`TypeError` on cost/duration formatting. A `logger.debug` in the `except` would cost nothing. Still non-blocking.

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VERDICT: approve

FINDINGS:
- [src/colonyos/orchestrator.py]: _extract_review_findings_summary blank-line handling is slightly loose — continues collecting past blank lines until a non-finding line. Not triggered by actual review template output. Non-blocking.
- [src/colonyos/orchestrator.py]: _format_task_list_with_descriptions silently swallows ValueError/TypeError on cost/duration formatting — a logger.debug would aid debugging. Non-blocking.

SYNTHESIS:
This is good, clean work. The data structures are right — task descriptions and review findings extracted from existing artifacts with simple string operations, no regex gymnastics, no new LLM calls, no clever abstractions. The three-tier fallback in `_extract_review_findings_summary()` (FINDINGS → SYNTHESIS → first line) handles real-world variance without overengineering. The sanitization architecture is correct: double-layer sanitization applied at the content boundary, not the output boundary. Named constants make the truncation limits grep-able. 135 tests cover the formatting functions, sanitization edge cases, and constant values. The fix iteration cleanly addressed all prior round findings — hardcoded magic numbers replaced with the named constant, bare link regex expanded to close the scheme asymmetry, audit logging added. The code does what it says, doesn't try to be clever, and the data structures tell me exactly what's happening. Ship it.
