Cover the Linux branches in prefs.py that previously had no tests
(font metrics, GPU spoofing, MSAA from profile, canvas noise mask
per renderer, WebGL extension preservation, Xvfb workarounds,
virtual_display no-op) and add construction smoke tests for
_LinuxVirtualDisplay. Also fix two host-platform-dependent tests
so the suite stays green on both Windows and Linux.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Final sweep adds unit tests for the modules left at 0% direct coverage
after Phases 1-9:
- launcher._tz_env: 7 tests covering the IANA -> POSIX mapping
including the Phoenix / Honolulu no-DST regression cases
- launcher._humanize_max_seconds, _default_context_kwargs: 11 tests
on the constructor-side helpers (no browser launch)
- _headless.make_virtual_display dispatcher + _WindowsVirtualDesktop
init/teardown: 8 tests (Linux dispatch branch covered without
spawning Xvfb, since __init__ does no I/O)
- async_api.InvisiblePlaywright constructor parity with sync: 8 tests
guarding against drift between the two APIs
Suite: 230 -> 264 passing. Pyramid stays clean: 243 unit / 12
integration / 9 e2e.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
