design variants --count abc silently generated ZERO variants and exited 0:
parseInt(NaN) flowed through Math.min into the generation loop bound. The
same NaN class was live on the two sibling flags in the same file:
--retry abc made generate() a silent no-op (attempt <= NaN never true, null
output, exit 0) and --timeout abc killed the serve board ~immediately
(setTimeout(NaN)).
New design/src/flag-utils.ts: parseIntFlag (pure, unit-testable) +
normalizeIntFlag (CLI wrapper). Contract matches the --viewports precedent
(error loudly on nonsense — these commands spend real image-API money, a
silent fixup hides typos from calling agents): undefined -> default; bare
flag/empty/non-integer ("3.7" rejected, not truncated)/below-min -> exit 1
with usage hint; above-max -> clamp with stderr warning. --count normalizes
at the variants() consumption site so programmatic callers are covered, with
the ceiling derived from STYLE_VARIATIONS.length instead of a magic 7; the
CLI passes the raw flag through (a pre-parseInt would truncate "3.7").
Tripwires live in test/design-flag-utils.test.ts — deliberately under test/,
not design/test/, which is invisible to the bun test glob, TEST_ROOTS, and
every workflow (wiring design/test/ into CI is a captured TODO).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Garry Tan