The plan asked for jsdom AND Playwright from the start and only jsdom was
ever built. jsdom has no layout engine: getBoundingClientRect answers zeros,
container queries never fire, a theme is an attribute rather than a computed
cascade. So every claim about POSITION or SIZE in this kit was unchecked, and
the unit suite could not have noticed either of these.
A popover bounded its height and not its width. `max-height: 60vh` was there
from the start; there was no max-inline-size at all, so a long unbroken
string -- a file path, a model filename -- made the popover wider than the
screen and anchor.js could not save it: it can move a box, not shrink one.
Measured at 1436px inside a 1280px viewport, off the right edge in all four
corners.
A horizontal split could not fit a narrow screen. The first pane carries an
inline size and `flex: 0 0 auto`, so it would not shrink, and the page
scrolled sideways at 360px -- 407px of content in a 360px viewport. It wraps
now, which stacks the panes, rather than a media query: the kit sizes itself
from its container and not from the window.
Nine layout tests: every overlay corner, an overlay taller than the viewport,
both themes resolving every token they use, light actually being lighter than
dark, and no horizontal scrollbar at five widths. `npm run test:all` runs both
suites.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
register/zlayer/anchor/motion/density are pure cores over plain data, so most of
the suite runs with no DOM at all; jsdom covers only what is genuinely DOM.
100 tests, zero elements.
These five are why v4 had 11 hand-built modals and 7 hand-built popovers: there
was nothing shared to reuse. register makes an element exist only because a file
defined it; portal gives every overlay one stacking parent; zlayer owns the only
z-index in the app; dismiss keeps one stack so Escape pops the top and not the
modal underneath; anchor measures, flips and clamps once.
Three bugs the tests found: unmount() called removeChild on null when no portal
existed yet, focusables() checked aria-hidden on the element instead of its
ancestors so a hidden subtree stayed tab-reachable, and the density ratios v4
hand-tuned are now derived from the gap they were meant to allow for.
Claude