How to get a BuildContext from WidgetTester?

Question

When doing a Flutter widget test, I can get a context from the WidgetTester if I know something about at least one widget in the tree. E.g., if I know there's a Text widget in the test widget tree, I can

BuildContext context = tester.element(find.byType(Text));

How can I get a context more generally? E.g., can I get the root widget of the tree and get its BuildContext?

Answer 1

Declare a navigatorKey using

GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();

Assign this navigatorKey to your material app widget in your test class.

await tester.pumpWidget(
  MaterialApp(
    home: const Scaffold(),
    navigatorKey: navigatorKey,
  ),
);

Then you will be able to access its context using navigatorKey.currentContext.

Note that there must be a widget in the tree (in this case a Scaffold) otherwise navigatorKey.currentContext will be null.