Unit testing in Flutter passing BuildContext

Question

I have a method in a Dart class, which accepts BuildContext parameter, as follows:

class MyClass {    <return_type> myMethodName(BuildContext context, ...) {         ...         doSomething         return something;     } } 

I want to test that the method works as expected:

import 'package:flutter/material.dart'; import 'package:flutter_test/flutter_test.dart'; import 'package:mockito/mockito.dart'; ...  void main() {   MyClass sut;    setUp(() {     sut = MyClass();   });    test('me testing', () {      var actual = sut.myMethodName(...);              expect(actual, something);   }); } 

Of course, it won't work, because the method myMethodName needs a parameter BuildContext type. This value is available throughout the application itself, but not sure where to get that from in my unit tests.

Answer 1

One way is to use testWidgets in combination with a Builder widget:

testWidgets('me testing', (WidgetTester tester) async {   await tester.pumpWidget(     Builder(       builder: (BuildContext context) {         var actual = sut.myMethodName(context, ...);         expect(actual, something);          // The builder function must return a widget.         return Placeholder();       },     ),   ); });