[ptinsley]

Why

main.go had drifted out of gofmt compliance and nothing in the build fails over it, so it stayed that way silently. This formats it, writes down the convention, and then makes the convention mechanical so it does not depend on anyone remembering.

1. The formatting sweep (f846523)

Only main.go was affected — 26 lines, no behaviour change:

• one out-of-order import (kingpin sorted after google.golang.org/api/option)
• gofmt's //Comment → // Comment rule, which has applied since Go 1.19 and accounts for all but one line of the diff

Kept as its own commit so it never has to be read alongside a real change. gofmt -l . now prints nothing.

2. CLAUDE.md (ce41922)

The repo had no CLAUDE.md. Formatting leads, since that is what prompted this: run gofmt -w . before every commit, and keep a formatting sweep out of a behaviour change so the substantive diff stays readable.

It also records the decisions from #3 that are cheap to undo by accident and expensive to rediscover:

• the emulator tests must never become skippable — a green run that quietly tested nothing is worse than a red one
• every wait in the integration suite is a bounded assertion, not a sleep
• fixture setup belongs before fling starts and appends after, because that split is what the read_from_beginning and tail-mode scenarios exist to test
• there is one go.mod on purpose

3. The gofmt hook (963539e)

A written convention only works when someone remembers it. .claude/settings.json adds a PostToolUse hook so that after any Write/Edit/MultiEdit, .go files are formatted in place.

Guards on the .go suffix, and cannot fail a tool call — a missing path or a gofmt error is swallowed.

Verified by piping the exact stdin payload the hook receives:

Input	Result
misformatted .go file	corrected (func F( ) int → func F() int)
.txt file	skipped, unmodified
empty path	clean exit

Then verified end-to-end in a live session: a deliberate func lineTimeAt(offset int) written through Edit came back correctly formatted, with git diff empty.

Note for reviewers: the hook does not take effect in a session that was already running when .claude/settings.json first appeared — the settings watcher only monitors directories that had a settings file at startup. Open /hooks once, or start a new session.

Limits worth knowing

The hook only fires on Write/Edit/MultiEdit. A .go file produced by a script or a go command will not trigger it, which is why CLAUDE.md still asks for a gofmt -l . check before committing rather than treating the hook as complete coverage.

Verification

gofmt -l . empty, go build, go vet, and go test ./... all clean — 30 tests, 42 subtests, 10 emulator scenarios.

🤖 Generated with Claude Code