X renders its chat inside an open shadow root since 2026-10-01 (the XChatEmbed
host [data-testid=xchatEmbedRoute]); the hub's document observer saw nothing
of it, selector observers found nothing, feature sheets in <head> did not
reach it and probes could not see it.
A site adapter may name shadowHosts. The hub's one MutationObserver then also
observes each such root (picked up on the next page mutation, or a few timed
retries while a host has no root yet; dropped with the observer), selector
observers search the roots too, domRoots(win) gives features the roots, a
feature's ctx.css sheet is also adopted by each root (CSP-proof, updated in
place, taken off on stop), and probes count matches inside the roots.
Tests: hub observes and searches a root that appears later with one
observer; registry adopts and removes the sheet and a probe inside a root is
never a miss.
Site-agnostic parts of the X app, behind a small site adapter:
- crates/waybetter-host: webview-label security policy and tab rect
clamp, account profiles with native-owned accounts (AccountRules),
plugin store with bundled-plugin upgrades (PluginHost), signed
data-only hotfix channel, update scheduling and crash handshake, tab
payloads/link routing/tab-chrome validation, and (feature "tauri")
webview helpers and the Windows system menu.
- packages/runtime: DOM hub, request hub, plugin API core, OKLab theme
color model, split-view rail hiding, link routing and account
reporting, each configured by a SiteAdapter.
- packages/shell: address bar, pane, link-drop, profile, palette and
update-chip models, and window controls with the Tauri API injected.
Tests moved/adapted from the app: 45 Rust (headless), 40 TypeScript.
