Write widget test for top navigation using tabs

[nathanbaleeta]

To ensure theU-Report app continues to work as developers add more features or change existing functionality, writing tests for every custom built widget should be an integral part of the development process.

Unit tests are handy for verifying the behavior of a single function, method, or class. The test package provides the core framework for writing unit tests, and the flutter_test package provides additional utilities for testing widgets.

Carry out following steps to add a widget test for the tog navigation widget:

• [x] Create a new branch from develop called top-navigation-test. Hint: git checkout -b new-branch existing-branch
• [x] Add the test dependency. Confirm flutter_test package is added to pubspec.yaml file under dev_dependencies section.
• [x] Create a new file dart file under test/ folder and name it top_navigation_widget_test.dart
• [x] Open top_navigation_widget_test.dart file and import following packages: import ‘package:flutter/material.dart’; import ‘package:flutter_test/flutter_test.dart’;
• [x] Write a test for the tab navigation widget.
• [x] Combine multiple tests in a group.
• [x] Run the tests in terminal using: flutter test test/top_navigation_widget_test.dart
• [x] Commit the changes (as a single commit).
• [x] Push changes to Github. Hint: git push --set-upstream origin top-navigation-test
• [x] Open a pull-request.

Hints: https://medium.com/flutterpub/writing-and-running-widget-tests-from-android-studio-d63b9fea21c5 https://flutter.dev/docs/cookbook/testing/unit/introduction

[nathanbaleeta]

Removed widget test for DefaultTabController tab-pressing callback validation to avoid tests for the tab views failing in the future.