fmt-sweep

name	fmt-sweep
description	Fix a red "Format & clippy" (rust.yml) CI job on kymostudio — auto-apply cargo fmt, verify the exact CI lint gate goes green, and ship the fix. Use when a Rust core CI run fails on the rustfmt or clippy step, or to pre-empt one before pushing Rust changes. Formatting is deterministic and non-semantic, so the fmt fix is safe to auto-apply; clippy failures are surfaced, not blindly rewritten.
when_to_use	A `Rust core` workflow run is red on rustfmt/clippy, or before pushing changes under packages/rust/.
argument-hint	[run-id]
allowed-tools	Bash Read Edit Grep

The Rust CI sweeper loop. Pattern: Retry (atomic, mechanical). The goal contract is the exact lint gate .github/workflows/rust.yml runs — nothing looser.

Goal contract (what "green" means)

Two working directories, the same commands CI uses:

# in packages/rust/kymostudio-core
cargo fmt --all --check
cargo clippy --all-targets -- -D warnings
cargo clippy --all-targets --features bpmn -- -D warnings
cargo check --no-default-features
cargo clippy --lib --no-default-features --features wasm,pdf --target wasm32-unknown-unknown -- -D warnings
# in packages/rust/kymostudio
cargo fmt --all --check
cargo clippy --all-targets -- -D warnings

cargo fmt --all here also reformats local path-dependency crates (e.g. kymo-layout, kymo-mermaid), which is why a fmt break in a sibling crate surfaces in this job.

Loop

1. Identify (optional $1 = failing run id): confirm which step is red.

   gh run view "$1" --json jobs -q '.jobs[] | select(.name=="Format & clippy") | .steps[] | select(.conclusion=="failure") | .name'
   

2. See the diff (don't fix blind):

   cd packages/rust/kymostudio-core && cargo fmt --all --check
   

3. Auto-apply the fmt fix (deterministic — safe to apply without classifying):

   cd packages/rust/kymostudio-core && cargo fmt --all
   cd ../kymostudio && cargo fmt --all
   

4. Re-verify the whole gate (step "Goal contract" above). The fmt clauses must now pass.
   • If a clippy clause is red, stop and report it — -D warnings failures can be semantic (unused result, needless clone). Surface the lint; let a human decide the fix. Do not clippy --fix blindly in this loop.
5. Scope check: git diff --stat should touch only whitespace/formatting in the offending crate(s). Any logic change means fmt rewrote something unexpected — review before shipping.
6. Ship: branch fix/rust-fmt, commit style(rust): cargo fmt <crate> (no AI-attribution trailer), open + merge a PR with gh (repo uses --merge, squash is disabled).

Output

Report: which crate/file was mis-formatted, the git diff --stat, the final gate verdict (all clauses pass), and the merged PR URL. If clippy was red, report the lint instead of shipping and hand back to the user.