Write further tests

Problem/Motivation

We already implemented a couple of tests through: 📌 Write tests Needs work . To ensure, that the module has full test coverage, we should implement further tests.

Steps to reproduce

Proposed resolution

Write tests:

1. [ ] Test caching (PP on 📌 Make dropdown language block cacheable Postponed )
2. [ ] Test the different cases/conditions in https://git.drupalcode.org/project/dropdown_language/-/blob/4.0.x/src/Pl... aka /admin/config/regional/dropdown-language-switcher
3. [ ] Add tests to ensure functionality with the content AND interface dropdown block in conjunction
4. [ ] ???

Remaining tasks

User interface changes

API changes

Data model changes