fix(slack): preserve complete executor summaries safely

[gabiIsCoding]

Problem

Slack final replies could silently discard most executor output: only the first paragraph was selected, the remaining text was capped at 360 characters, and shared whitespace normalization collapsed line breaks.

Fix

• Preserve the complete final summary, including paragraph breaks.
• Prefer the dedicated What changed section when the executor returns a structured summary.
• Normalize CRLF and lone CR without flattening multiline output.
• Convert Markdown to Slack mrkdwn before applying a 2500-character summary cap, leaving room under Slack's 3000-character section limit.
• Truncate on Unicode code-point boundaries so emoji cannot leave lone surrogate characters.
• Keep shared compact fields such as next actions on one line.
• Mark provider-rendered callback bodies as Slack mrkdwn so chat.postMessage and chat.update do not encode entities and links twice.
• Escape plain Slack fallbacks for doctor summaries and source-thread status without changing their blocks.

Regression coverage

• Multi-paragraph summaries and blank lines are preserved.
• Escaping expansion remains within the Slack section limit.
• Emoji boundary truncation produces well-formed Unicode.
• Compact one-line fields still collapse whitespace.
• The complete presentation-to-callback path preserves entities and Slack links for both post and update payloads.
• Doctor and source-thread Slack fallbacks escape entities and convert Markdown links while other providers stay plain.

Verification

• pnpm build
• pnpm lint
• pnpm typecheck
• pnpm test — 119 test files, 1517 tests passed
• Focused Slack renderer and dispatcher callback suites — 82 tests passed
• git diff --check

Files changed

• packages/slack/src/render.ts
• packages/slack/test/render.test.ts
• packages/dispatcher/src/callbacks.ts
• packages/dispatcher/test/callbacks.test.ts
• packages/dispatcher/src/presentation.ts
• packages/dispatcher/test/presentation.test.ts

Summary by CodeRabbit

• Bug Fixes
  • Improved Slack “Finished”/final summary rendering: consistent newline normalization, better selection of the “What changed” section, cleaner header handling, and safer mrkdwn truncation within Slack limits.
  • Prevented double-encoding by introducing an explicit textFormat option for Slack message payloads (and setting it to mrkdwn in the callback flow).
  • Updated Slack doctor/source-thread presentations to render bodies as Slack-compatible MRKDWN when supported.
• Tests
  • Added/expanded Vitest coverage for Slack Block Kit compliance, CRLF/CR newline behavior, Unicode-safe ellipsis truncation, compact “next action” formatting, and mrkdwn escaping in both top-level text and blocks.

[coderabbitai]

📝 Walkthrough

Walkthrough

Slack final summaries now normalize multiline content, select compact sections, truncate rendered mrkdwn to 2500 characters, and use explicit mrkdwn handling for Slack callbacks and Slack presentation fallbacks.

Changes

Slack rendering and callback delivery

Layer / File(s)	Summary
Slack text and summary formatting packages/slack/src/render.ts	Compact summaries normalize content, select the What changed section when available, remove leading headers, and truncate rendered mrkdwn to 2500 characters for string and Block Kit final summaries.
Explicit mrkdwn payload handling packages/slack/src/render.ts, packages/dispatcher/src/callbacks.ts	Post and update payload builders accept textFormat; Slack callback delivery marks pre-rendered content as mrkdwn to avoid double conversion.
Slack presentation fallback formatting packages/dispatcher/src/presentation.ts	Doctor and source-thread Slack fallback bodies are converted to Slack-compatible mrkdwn while other providers retain their existing output behavior.
Rendering and callback validation packages/slack/test/render.test.ts, packages/dispatcher/test/callbacks.test.ts, packages/dispatcher/test/presentation.test.ts	Tests cover escaping, Slack length limits, newline normalization, Unicode-safe truncation, compact next-action text, provider-specific output, and correctly encoded callback payloads.

Estimated code review effort: 3 (Moderate) | ~25 minutes

Possibly related PRs

• amplifthq/opentag#7: Related Slack callback payload construction and mrkdwn handling.
• amplifthq/opentag#56: Related Slack final-summary compaction and rendering changes.

Suggested reviewers: mingyooagi

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title is concise and accurately reflects the main change: safely preserving complete Slack executor summaries.
Description check	✅ Passed	The description includes the needed problem, fix, validation, and notes-style details, though it uses different headings than the template.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/slack-summary-truncation

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[gemini-code-assist]

Code Review

This pull request updates the Slack text rendering logic by changing how text is normalized and increasing the summary truncation limit from 360 to 2800 characters. Feedback suggests lowering the truncation limit to 2500 to safely accommodate character escaping and prepended text within Slack's 3000-character limit. Additionally, it is recommended to update the line ending normalization regex to handle classic Mac OS line endings as well.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/dispatcher/src/callbacks.ts`:
- Around line 462-469: Escape the fallback Slack text before passing
message.body to createSlackPostMessagePayload with textFormat "mrkdwn". Update
the relevant callback path, including doctor_summary and source_thread_status
flows, to apply the existing Slack mrkdwn escaping utility while preserving the
current blocks and message structure.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 40ace511-90d2-4da8-a581-2d06fbd03b57

📥 Commits

Reviewing files that changed from the base of the PR and between 824a6b3 and f0c442a.

📒 Files selected for processing (4)

• packages/dispatcher/src/callbacks.ts
• packages/dispatcher/test/callbacks.test.ts
• packages/slack/src/render.ts
• packages/slack/test/render.test.ts