Unit testing

[Rkareko]

IMPORTANT: Where possible all PRs must be linked to a Github issue

Part of fix for ##56

Type Choose one: (Bug fix | Feature | Documentation | Testing | Code health | Release | Other)

Checklist

• [ ] I have written Unit tests for any new feature(s) and edge cases for bug fixes
• [ ] I have added any strings visible on UI components to the strings.xml file
• [ ] I have run ./gradlew spotlessApply and ./gradlew spotlessCheck to check my code follows the project's style guide