Function TestFinishNeverStarted

cpp/src/arrow/util/task_group_test.cc:330–335

}

void TestFinishNeverStarted(std::shared_ptr<TaskGroup> task_group) {
  // If we call FinishAsync we are done adding tasks so if we never added any it should be
  // completed
  auto finished = task_group->FinishAsync();
  ASSERT_TRUE(finished.Wait(1));
}

void TestFinishAlreadyCompleted(std::function<std::shared_ptr<TaskGroup>()> factory) {
  // If we call FinishAsync we are done adding tasks so even if no tasks are running we