To audit what each UI test actually exercises, every step now snapshots the
live window to <TestFixtureName>/<TestName>_<NN>_<ShortDescription>.png: a
booted frame (emitted automatically by TestHarness.BootAsync), one after each
state-changing action, and one before each assertion. Flip ILSPY_TESTS_VISIBLE=1
to render the filmstrip; it lands under %TEMP%/ilspy-test-captures (overridable
via ILSPY_TEST_CAPTURES).
The step number and fixture/test name are derived automatically so inserting a
breakpoint never renumbers the rest. The identity is recorded up front from the
real ITest in an ITestAction hook rather than read live: NUnit's
TestContext.CurrentContext does not flow onto async continuations, so a capture
after an await would otherwise collide under the ad-hoc context. And when
rendering is off the whole call is a true no-op -- not even a dispatcher pump --
so instrumenting a test can never perturb the navigation/tab timing it asserts
on. Full headless suite stays green.
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.
Mirrors the WPF AssemblyTreeNode.SetPublicAPI recursive walk: a namespace
counts as public-API iff at least one type it contains is public-API. Inline
on NamespaceTreeNode itself as a lazy-evaluated cached aggregate (types don't
change accessibility at runtime), so the cell template's gray-foreground
binding picks up the right value on first render.
Assisted-by: Claude:claude-opus-4-7:Claude Code
Replaces the brittle root.GetVisualDescendants().OfType<T>().Single() / .First()
pattern with a new WaitForComponent<T>() extension that polls until the requested
control is in the visual tree, then returns it. Avalonia.Headless tests routinely
queried the visual tree before lazily-templated panes (DataGrid, dock content)
had materialised, surfacing as intermittent 'Sequence contains no elements'
failures across the suite.
Assisted-by: Claude:claude-opus-4-7:Claude Code
Siegfried Pammer