In 'full tree' widget tests instead of writing widget tests exercising just 1 widget in separation, we set up the whole path user would have to follow to get to this widget.

It's similar to writing integration tests, but these tests are faster and interact with mocks instead of making real API calls. It’s easy to test happy paths, but also error scenarios and timeouts. Another benefit of those tests is quickly increasing test coverage, as many layers of the app are tested at the same time. This makes refactoring easier - tests will check if all parts of the app still behave as expected.

Talk agenda:
-when to use full tree tests and when plain widget tests are enough
-what can you test with it
-advantages over using widget tests or integration tests
required setup
-common problems