fix(engine): keep renderRepoMap's output within maxOutputChars including the marker (#9617)

[RealDiligent]

Problem

Closes #9617.

renderRepoMap (packages/loopover-engine/src/miner/repo-map.ts) is documented as a bounded outline, but pushLine budgets only content lines — the truncation marker was appended via lines.push unbudgeted, so a truncated result overshot maxOutputChars by up to the marker's length + a newline, and when the first line alone exceeded the budget it returned only an over-budget marker. maxOutputChars is a token-budget guarantee the prompt packet relies on.

Fix

Reserve the marker from the budget (extracted to a TRUNCATION_MARKER const):

• Not truncated → return the join unchanged (byte-for-byte identical, no reserved headroom).
• Truncated → drop trailing content lines until the marker (plus its joining newline while content remains) fits, then append it, so result.length <= maxOutputChars always.
• maxOutputChars < marker length → return the empty string, never an over-budget marker.

Tests

test/unit/repo-map.test.ts: tightened the truncation test to the strict <= maxOutputChars bound; added a case asserting the bound across a spread of budgets and that a sub-marker budget yields "" while a marker-sized budget yields the marker alone; updated the four break-site tests to the new contract. 100% line + branch coverage on the changed file (verified via lcov: 119/119 lines, 90/90 branches).

[loopover-orb]

Caution

🛑 LoopOver review result - fixes required

_{Review updated: 2026-07-29 01:55:10 UTC}

2 files · 1 AI reviewer · no blockers · CI failing · unstable

🛑 Suggested Action - Fix Blockers

Review summary
This is a scoped, correct fix for #9617: `TRUNCATION_MARKER` is extracted to a const and reserved from the budget via a pop-until-it-fits loop before being appended, so `renderRepoMap` now guarantees `result.length <= maxOutputChars` in all cases, including returning `""` when the budget can't even hold the marker. I traced the `length`/pop bookkeeping (repo-map.ts:405-411) against `pushLine`'s accounting and it's internally consistent — the `lines.length === 0 ? removed.length : removed.length + 1` subtraction correctly mirrors how each line's length was added, and the non-truncated path is returned unchanged with no reserved headroom as claimed. Tests were rewritten to the new `<=` contract and add real coverage of the three break sites plus the sub-marker-budget empty-string case.

Nits — 5 non-blocking

• The PR description claims '100% line + branch coverage… 119/119 lines, 90/90 branches' but CI STATUS shows codecov/patch FAILED at 22.22% of diff hit (target 99%) — worth reconciling before merge since the two numbers can't both be right for the same diff.
• repo-map.ts:344-346: the new marker-reservation doc comment duplicates most of the existing function-level doc above it; could be folded into one comment block instead of two adjacent ones.
• The external brief flags `9617` as an unexplained magic number in the new comment (repo-map.ts:345) — it's just an issue-reference in prose, not a literal used in logic, so this is a non-issue, but a `// see engine(repo-map): renderRepoMap's truncation marker is appended outside its own char budget #9617` style citation is slightly cleaner if you want to placate coverage-of-comments tooling.
• Confirm the codecov/patch failure isn't hiding an actual untested branch (e.g. the `lines.length === 0` ternary arm inside the pop loop at repo-map.ts:409) despite the description's claimed 100% coverage.
• Consider a short inline comment on the pop-loop's length bookkeeping (repo-map.ts:406-411) since the off-by-one-newline accounting is subtle enough that a future edit could break it silently.

CI checks failing

• codecov/patch — 55.55% of diff hit (target 99.00%)

Decision drivers

• ✅ Code review — No blockers (1 reviewer)
• ✅ Gate result — Passing (No configured blocker found.)

Context & advisory signals — never blocks the verdict

Signal	Result	Evidence
Linked issue	✅ Linked	#9617
Related work	✅ No active overlap found	No same-issue or scoped active PR overlap found.
Change scope	✅ 20/20	Low review scope from cached public metadata (1 linked issue).
Validation posture	❌ 5/25	Preflight is holding this PR: the review lane is unavailable, so it is not ready for automated review.
Contributor workload	✅ 10/10	Author activity: 266 registered-repo PR(s), 111 merged, 37 issue(s).
Contributor context	✅ Confirmed Gittensor contributor	RealDiligent; Gittensor profile; 266 PR(s), 37 issue(s).
Improvement	✅ Minor	risk: clean · value: minor · LLM: moderate

Linked issue satisfaction

Partially addressed
The core budgeting bug is genuinely fixed: the marker is now reserved via a post-hoc trim loop so truncated output stays within maxOutputChars, a too-small budget returns "", and the non-truncated path is left byte-for-byte unchanged, matching the issue's algorithmic requirements while preserving the pushLine/outer-loop structure. However, several deliverables are only loosely matched rather than

Review context

• Author: RealDiligent
• Role context: outside_contributor
• Public audience mode: oss maintainer
• Lane context: Repository is registered but has no active allocation in the current snapshot.
• Public profile languages: not available
• Official Gittensor activity: 266 PR(s), 37 issue(s).
• PR-specific overlap: none found.

Contributor next steps

• Start here: Await review-lane availability.
• Then work through the remaining 2 steps in the Signals table above.

Signal definitions

• Related work = same linked issue, overlapping active PRs, or title/path similarity.
• Change scope = cached public metadata such as size labels, draft state, and review-burden hints.
• Validation posture = whether the PR provides enough public validation/test evidence for maintainer review.
• Contributor workload = public contributor activity and cleanup pressure, not a repo-wide quality failure.
• Contributor context = public GitHub/Gittensor identity context; non-Gittensor status is not a blocker.

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_{🟩 Safe / merged · 🟦 Advisory · 🟨 Held for review · 🟥 Blocked / closed}

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[superagent-security]

Superagent didn't find any vulnerabilities or security issues in this PR.

[codecov]

Codecov Report

❌ Patch coverage is 55.55556% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.07%. Comparing base (8e3e4f5) to head (c11ab36).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/loopover-engine/src/miner/repo-map.ts	55.55%	8 Missing ⚠️

❌ Your patch check has failed because the patch coverage (55.55%) is below the target coverage (99.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9628      +/-   ##
==========================================
- Coverage   90.08%   90.07%   -0.01%     
==========================================
  Files         889      889              
  Lines      112024   112041      +17     
  Branches    26587    26590       +3     
==========================================
+ Hits       100921   100926       +5     
- Misses       9773     9781       +8     
- Partials     1330     1334       +4     

Flag	Coverage Δ
backend	95.56% <100.00%> (-0.01%)	⬇️
engine	66.85% <22.22%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
packages/loopover-engine/src/miner/repo-map.ts	66.00% <55.55%> (-0.58%)	⬇️

... and 1 file with indirect coverage changes

[loopover-orb]

LoopOver is closing this pull request on the maintainer's behalf (CI is failing (codecov/patch)). This is an automated maintenance action — to pursue this change, please open a new pull request with the issues resolved. Closed PRs may be analyzed later to improve review accuracy, but they are not automatically reopened or re-reviewed.