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.
SessionSettings now carries HideEmptyMetadataTables (default true,
matching prior behavior) and MetadataTablesTreeNode honors it: when
true, tables with zero rows are hidden; when false, every CLI
TableIndex is surfaced. The setting persists across launches via
ILSpy.xml. There's no options dialog yet to flip it, but the plumbing
is in place for a future settings UI to toggle.
Assisted-by: Claude:claude-opus-4-7:Claude Code
Siegfried Pammer