setUpAll function Null safety

void setUpAll(
  1. dynamic body(
      )
    )

    Registers a function to be run once before all tests.

    The body may be asynchronous; if so, it must return a Future.

    If this is called within a test group, The body will run before all tests in that group. It will be run after any setUpAll callbacks in parent groups or at the top level. It won't be run if none of the tests in the group are run.

    Note: This function makes it very easy to accidentally introduce hidden dependencies between tests that should be isolated. In general, you should prefer setUp, and only use setUpAll if the callback is prohibitively slow.

    Implementation

    void setUpAll(dynamic Function() body) {
  _declarer.setUpAll(body);
}