Nearly every headless UI test opened with the same four-line prologue
(resolve the shared MainWindow, show it, cast its DataContext, wait for the
assembly list), then repeated the corelib lookup, the EnsureLazyChildren +
Children.OfType<T>().Single() drill, the registry single-by-header lookups,
and the open-an-assembly-and-wait dance. The duplication made the intent of
each test hard to see and every signature tweak a suite-wide edit.
Collapse those into TestHarness (BootAsync, OpenAssemblyAsync, GetCommand,
GetEntry) and TreeNavigation extensions (FindCoreLib, GetChild<T>, Expand<T>),
then apply them across the suite. Net ~865 lines of boilerplate removed with
no change in behaviour; the full headless suite stays green.
Sweep-up commit. The dotnet-format pre-commit hook keeps re-ordering
these usings on every other commit; landing them once stops the hook
from grumbling at unrelated diffs going forward.
Assisted-by: Claude:claude-opus-4-7:Claude Code
Closes the third logged analyzer follow-up. When the user double-clicks an
analyzer result (e.g. one of the methods listed under "Used By" on Foo.Bar),
the decompiled-output view now paints local-reference marks on every
mention of the originally-analysed entity inside the navigated-to body —
so the user can spot the exact call site the result row corresponds to.