A non-`auto` `scrollbar-width` or `scrollbar-color` makes Chromium and Safari
discard every `::-webkit-scrollbar*` rule for that element, including
`::-webkit-scrollbar-thumb:hover`. Declaring both unconditionally left the
hover tokens rendering nowhere: the engines implementing the hover
pseudo-element are exactly the ones the standard properties silence, and
Firefox has no hover pseudo-element to fall back on. Both hover tokens and all
four elevated surfaces' hover rebinds were therefore dead code.
Measured in chromium on probe elements with `scrollbar-gutter: stable`: an 8px
`::-webkit-scrollbar` alone reserved a 30px band, and adding
`scrollbar-width: thin` dropped it to the 10px `thin` reserves.
The standard properties now sit inside `@supports not
selector(::-webkit-scrollbar)`, so Firefox takes them and WebKit-based engines
take the pseudo-elements. The WebKit rules stay ungated: an engine without
those pseudo-elements drops them as unknown selectors, and gating them would
hide them from an engine that implements them without `selector()` — the
pre-16.4 Safari the ungated form serves correctly.
Three unit assertions pin the split by source offset, which the existing
at-rule-flattening parser cannot see. The web e2e now reads the path chromium
actually takes: the `auto` standard properties as the gate's signature, the
pseudo-element sizing and track, the indirection variables resolved per
throwaway probe, and the hover declaration as cascade rule text — chromium
folds the `:hover` rule into `getComputedStyle(el,
'::-webkit-scrollbar-thumb')`, so no computed query separates the states.
design-platform.css declared four --dsw-alias-scrollbar-* tokens in both
palettes that no rule read, so every scrolling region rendered the user
agent's own scrollbar and the dark theme showed a light native bar against
dark surfaces.
The symptom that surfaced the gap was in the sidebar: the workspace
browser's session list is its only scrolling region, and each row's
trailing content (the relative timestamp, and the hover action buttons
that replace it) is `flex: none` flush against the row's 8px right
padding, so an overlaid scrollbar painted on top of the timestamp.
ui-theme/styles/scrollbar.css becomes the sole consumer of the four
tokens, imported by the web shell's base.css after design-platform.css
because it reads that sheet's tokens. The rules sit on `body`, not
`html`: the alias tokens are declared on `body`, custom properties
inherit only downward, and from `html` they resolve to the
guaranteed-invalid value with scrollbar-color computing to `auto`.
scrollbar-width and scrollbar-color are declared on `body, body *` rather
than inherited, because inheritance would carry the color already
substituted at `body` and an elevated surface could not retint its own
thumb; scrollbar-width does not inherit at all.
Both the standard properties and the ::-webkit-scrollbar pseudo-elements
read one indirection pair bound to the l1 tokens, so an elevated surface
rebinds that pair to the l2 tokens once and retints both renderings. The
command popup, slash menu, model-select panel, and settings panel do so,
which gives the l2 tokens their first consumers.
WorkspaceBrowser's `.list` declares scrollbar-gutter: stable, keeping the
bar beside the rows. `stable` rather than `auto` so the reservation holds
when the list is short enough not to scroll: expanding a workspace group
would otherwise shift every row sideways at the moment it starts
scrolling.
Hand fixes for the findings --fix cannot touch, mirroring the fixes
already applied on the fe-docs feature branch (same file, same shape)
so its eventual rebase resolves cleanly:
- restore the return the no-confusing-void-expression autofix ate in
useAbsentSnapshot (typed S | undefined; hook call kept for hook-order
stability, undefined returned explicitly);
- re-type DOM queries the no-unnecessary-type-assertion autofix broke:
getByRole<HTMLButtonElement>(...) generics instead of the removed
as-casts (the eslint program and the client tsconfig aggregate
disagree about these casts; the generic form satisfies both);
- justified eslint-disable for the deliberate legacy paths: keyCode 229
IME-composition detection, execCommand clipboard fallbacks, lib.dom
clipboard optionality, and the any-typed Reflect.get/this probes in
test fakes;
- drop the dead react/no-danger directive (eslint-plugin-react is not
loaded, so the rule never applied) keeping its shiki rationale;
- delete the tautological 'Z' comparison and the renameTarget null
check already implied by renameBlocked;
- css-module non-null assertions replaced by type widening
(Button className, TAG_CLASS Record) per the established pattern;
- misc: max-len comment wraps, void generic drop in the deferred test
helper, unused type imports, floating selectWorkspace promises voided,
member-delimiter newlines in inline type literals.
unbound-method flags destructuring a method-style member (method
signatures are bivariant and exempt from the this-context check).
These contract members are all plain callbacks — declare them as
property-style function types so consumers can destructure them
without a false this-binding hazard. Type-level only.
Mechanical --fix output over the newly linted .tsx files (indent,
arrow-parens, comma-dangle, member-delimiter-style, unnecessary type
assertions), plus the three generic-arrow test hooks converted to
function declarations up front: the comma-dangle fixer strips the
<T,> disambiguation comma and turns them into parse errors otherwise.
The question composer card is capped against the viewport and scrolls its
option list. `.options` is a flex column whose children defaulted to
`flex-shrink: 1`, so a short seat shrank the rows before overflowing the
scroll container: a row collapsed to its 42px minimum while `.optionCopy`
kept the taller height its wrapped copy needs, and `align-items: center`
then painted that copy outside the row's border box — over the question
title above and the next row below. Measured 6.5px of spill at 900x440 on
the shipped client, 10px at 380px tall, with `.options` reporting
scrollHeight === clientHeight and therefore offering no scrollbar.
`.option` and `.custom` now declare `flex-shrink: 0`, so the shortfall
reaches the scroll container that already owns `overflow-y: auto` — the
behavior the cap was designed for. Only rows whose copy wraps could
reproduce this, which is why the recorded scenario now asks a question
with long option descriptions; the web e2e asserts at three squeezed seat
heights that every row's children stay inside its border box, guarded
against holding vacuously by requiring a wrapped row and a scrolling list.
The remote side re-merged master (i18n workflow round) and restored the
pre-architecture ModelSelector package with the Session-side state
machine. Reconciliation keeps that merge's master content and reasserts
this branch's model architecture: business state lives in ui-model's
shared per-session directory (ctx.models), not on Session/
ConversationSnapshot; the input.model seat entry and the /model popup
stay the two same-source entries; the history modelTarget piggyback stays
removed. The ui-model-selector package, its roster row, and its allowlist
entry go; the smoke-real roster names ui-model.
Chinesezjc
07akioni
imccyu
Tianyi Cui
_Kerman
NI0317
ZiyaZhang
fz
Yichen Jiang