was: `print_event` did the format + println inline; tests had a
parallel `captured` helper that re-implemented the dispatch and only
covered 4 of 14 event types. brittle — a new arm in `print_event`
silently went uncovered.
now: pure `format_event(ev: &Value) -> String` builds the line;
`print_event` is a thin wrapper that adds the trailing newline.
tests assert on `format_event` output directly so every new arm
gets test coverage by construction.
bonus: added 3 more test cases (assignees add/remove, pull_push
commit count + force-push, commit_ref sha truncation) since the
helper extraction made them cheap. 9 tests total, all green.
last unstarted piece of the original #694 epic. agents kept falling
back to curl for 'who closed this?' / 'when was this labelled?'
archaeology because view + comments only surface the body + comments,
not the structured timeline events (label adds, assignments, closes,
reopens, pushes, commit refs, review submissions, milestone changes).
separate verb rather than view --timeline because:
- composes naturally with view <n> / comments <n>
- keeps existing verb output shapes stable (no script breakage)
- argus on #770 already noted view's output is busy
human-readable by default ('**actor @ ts**: <summary>'), --json for
raw piping. unknown event types fall through to a '[<type>]'
placeholder so a forge schema bump doesn't panic the verb.
--tail N is a follow-up: timeline endpoint doesn't expose a total-count
field so the count-then-page strategy from #770 doesn't apply
directly.
6 tests cover comment / label add/remove / close / unknown-type
placeholder / missing-user fallback.
read the issue's `comments` count first, compute which page contains the
tail, fetch only `ceil(n/50) + 1` pages. drops the TAIL_MAX_PAGES cap
entirely — it was paging from the WRONG end (first 1000 comments instead
of the last n) on long threads, defeating the whole purpose of --tail.
work is now bounded by n, not by thread length.
