The existing UI test was passing too easily: every "if button.count() == 0:
log WARN" branch silently degraded into a green run. Three places this
hid real bugs:
1. The theme toggle for-loop bailed after cycle 1 because the Radix
Account-menu's data-state="open" lingered through the view-transition
and the next acct.click() hit the still-open dropdown. The test
went green observing only one polarity.
2. The regenerate button branch silently skipped when the assistant
action bar didn't render (every CI run so far -- the locator was
wrong, but no one noticed because it was a soft skip).
3. The Recents click accepted ANY non-nav sidebar entry, so a freshly
deleted thread or an unrelated entry would still pass.
Fixes:
- Add STUDIO_UI_STRICT=1 env (default on in CI via workflow,
default off locally). When on, every soft "if not visible: log
WARN" branch hard-fails. The strict-skip pattern is centralised
in a soft_fail() helper so the local-vs-CI split is one knob.
- Theme toggle: wait for [role="menu"] to detach between cycles
(the dropdown stay-open was the cycle-2 bail), assert the loop
actually ran 3 times.
- Model picker search: capture popover text after typing "qwen" vs
"llama"; the two snapshots must DIFFER, proving the typeahead
actually filters (a regression that rendered the picker but
ignored input would silently pass before).
- Recents click: after navigating to the clicked thread, the
rendered turns must include at least one of our sent prompts
("hello", "world", "tree", "1+1", etc.) -- proves we landed on
OUR thread, not a leftover from a previous run.
- Use [data-tour="chat-model-selector"] as the primary selector
for the model picker -- the guided-tour anchor is at least as
stable as anything else in the codebase (the tour breaks if it
moves), and there's no separate data-testid system to maintain.