isOffstage top-level constant
Asserts that the Finder locates a single widget that has at least one Offstage widget ancestor.
It's important to use a full finder, since by default finders exclude offstage widgets.
expect(find.text('Save', skipOffstage: false), isOffstage);
- isOnstage, the opposite.
const Matcher isOffstage = _IsOffstage();