Onboarding OpenHands.

OpenHands is a massive developer assistant platform. Onboarding its primary repository (300k+ lines of Python) to slop-mop required running sm refit to review all quality gates, establish baseline configurations, and execute step-by-step code remediation.

Onboarding Findings & Remediation

Running sm refit --start analyzed the project across all active checks, identifying findings in 7 different quality gates. The remediation path involved target refactoring alongside precise scoping configuration to lock down the codebase.

• Gate 1 · Deceptiveness: Bogus Tests

  “Python test files starting with test_ contained mock fixtures named test_client with no assertions. They were flagged as false-positive passing tests since they asserted no behavior.”

  Remediation: Renamed helper fixtures from test_client to client across all unit test suites, and added explicit assertions to helper validation routines.

• Gate 2 · Overconfidence: Missing Annotations

  “Strict type checking flagged thousands of missing parameter and return annotations across legacy abstract factory classes.”

  Remediation: Added targeted # type: ignore annotations for dynamic abstract imports and configured strict_typing: false scoped to core directories in .sb_config.json to prevent noise while preserving main type safety.

• Gate 3 · Myopia: Action Hygiene

  “A manifest builder job in _build-image.yml called actions/checkout without explicit contents: read permissions.”

  Remediation: Patched the GitHub Actions workflow permission blocks to explicitly grant read-only token permissions, securing the action checkout loop.

• Gate 4 · Overconfidence: Type Blindness

  “Strict pyright checking identified optional member access warnings (potential None attribute access) on serialization models and Litellm imports.”

  Remediation: Added targeted # type: ignore[reportOptionalMemberAccess] comments on optional fields, simplified import blocks, and resolved import-untyped risks.

• Gates 5 & 6 · Myopia: String Duplication and Code Sprawl

  “FastAPI query docstrings, large mock databases, and massive legacy service modules (some up to 1,700 lines) tripped length thresholds.”

  Remediation: Configured .sb_config.json to exclude test suites, scripts, and frontend directories from sprawl checks, and raised thresholds to lock in the legacy baseline length parameters.

• Gate 7 · Overconfidence: Coverage Gaps

  “Baseline project coverage check failed because the legacy codebase is at 49% coverage, falling short of the default 80% limit. Two sandbox port mapping tests were also failing.”

  Remediation: Set threshold: 49 in the configuration to freeze the baseline and prevent future regressions. Corrected the sandbox unit tests to assert string mappings for Docker ports rather than integer ports.

What was actually fixed — versus baselined

The findings above use the word “remediation” loosely. The split for a 400+-file PR whose bulk was reformatting: a small amount of fixing, and a large amount of accepting the existing state and guarding against regressions from there.

Read the green board that follows with that in mind: it is real, but it is the score for a deliberately scoped, baselined Python surface — not a claim that 322k lines got cleaned.

$ sm status

🪣 sm status — Project Status Check
🔀 Project: OpenHands
🔧 State: scour_clean

✨ MAINTENANCE MODE ACTIVE · 20/20 checks passed

   ✅ myopia:dependency-risk.py  (passed)
   ✅ myopia:github-actions-hygiene  (passed)
   ✅ myopia:ambiguity-mines.py  (passed)
   ✅ deceptiveness:bogus-tests.py  (passed)
   ✅ laziness:complexity-creep.py  (passed)
   ✅ laziness:dead-code.py  (passed)
   ✅ laziness:debugger-artifacts  (passed)
   ✅ overconfidence:coverage-gaps.py  (passed)
   ✅ overconfidence:missing-annotations.py  (passed)
   ✅ overconfidence:type-blindness.py  (passed)
   ✅ deceptiveness:gate-dodging  (passed)
   ✅ laziness:silenced-gates  (passed)

Executing sm status on OpenHands reports a clean slop-mop board (a dozen of the twenty shown) — slop-mop's own gate suite, now with the gate-dodging and silenced-gates meta-gates re-enabled in the second pass. That is a separate scoreboard from OpenHands' native CI; getting that green took the reconciliation in the ledger below — and as of this writing it is, with the PR passing every check and blocked only on a maintainer's review.

A second pass, looking for missed slop

We went back and looked for slop hiding behind the baseline. Little turned up. That is weak evidence either way: it is consistent with the code being in good shape, and also with our not having looked in the right places.

• The Python core is clean. Zero committed debugger artifacts; the lightweight, host-independent gates find essentially nothing to fix.
• Two meta-gates went back on. gate-dodging and silenced-gates both pass on this repo, so the baseline config isn't gaming the gates and no Python gate is muted. They are enabled again, asserting exactly that on every run.
• One genuine finding, fixed and verified. Tightening string-duplication surfaced the same FastAPI pagination Query() titles copy-pasted ~13× each across 11 routers — real duplication. We installed OpenHands’ toolchain, extracted them to shared constants in the existing paging_utils.py, and confirmed no behavior change (1,172 app-server and OpenAPI-schema tests still pass). With the duplication gone, the gate’s threshold drops from the baselined 20 back to 4 — a real tightening, earned by a real fix, not a config dial.

OpenHands runs its own eslint, tsc, ruff and mypy, all green, so much of what slop-mop downgraded overlapped with checks the host already ran, or was stricter than them. That is the strongest statement the evidence supports; it does not establish that nothing was missed. Raising the 49% coverage floor is left to the OpenHands team.

What went wrong

The board above is slop-mop's own gates. Getting OpenHands' native CI to pass — its ruff lint and its migration checks — took real work, and slop-mop made genuine mistakes getting there. We hold ourselves to the same standard we ask of our users: when the tool creates friction, file a barnacle. Here are the ones this case study produced, against our own repo.

• Misstep · It rewrote immutable migrations

  refit ran its formatters over 94 applied database migrations in enterprise/migrations/versions/. Applied migrations are historical records — they must never be reformatted. The change was simply wrong, and it tripped OpenHands' migration-check CI on top of it.

  Cost & fix: all 94 files were reverted to upstream. Filed as barnacle #263 — refit must exclude migrations/ and other immutable or generated trees from formatting. Still open at the time of writing.

• Wasted work · It double-formatted a repo that already had a formatter

  OpenHands already pins ruff (v0.12.5 / v0.4.1). refit reformatted 417 files with its own formatters anyway — and ruff promptly disagreed, demanding 139 fixes and 32 reformats. The work had to be redone with the host's ruff, partially undoing slop-mop's. Net result: churn, spent tokens, and a red lint board until it was reconciled by hand.

  Cost & fix: OpenHands' own ruff hooks were run and committed. Filed as barnacle #264 — when a repo pins a formatter, refit should defer to it, not fight it.

• Framing · "Maintenance Mode" is not "your CI is green"

  A 20/20 slop-mop board means slop-mop's gates pass. It does not mean OpenHands' native pipeline passed — that needed the two fixes above, plus keeping the branch synced with a fast-moving main. Onboarding earns you a baseline; it does not hand you a green host pipeline for free.

  Takeaway: the slop-mop board and the host's CI are two separate scoreboards. PR #14719 shows both.