[Testing] Increasing test coverage and refactoring for better clarity

[komer3]

General:

• [ ] Have you removed all sensitive information, including but not limited to access keys and passwords?
• [ ] Have you checked to ensure there aren't other open or closed Pull Requests for the same bug/feature/question?

Pull Request Guidelines:

1. [ ] Does your submission pass tests?
2. [ ] Have you added tests?
3. [ ] Are you addressing a single feature in this PR?
4. [ ] Are your commits atomic, addressing one change per commit?
5. [ ] Are you following the conventions of the language?
6. [ ] Have you saved your large formatting changes for a different PR, so we can focus on your work?
7. [ ] Have you explained your rationale for why this feature is needed?
8. [ ] Have you linked your PR to an open issue

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 69.23077% with 8 lines in your changes missing coverage. Please review.

Project coverage is 56.65%. Comparing base (e54da7d) to head (fc85c39). Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/filesystem/filesystem.go	0.00%	4 Missing :warning:
internal/driver/nodeserver.go	33.33%	2 Missing :warning:
main.go	0.00%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #264 +/- ## ========================================== + Coverage 53.02% 56.65% +3.63% ========================================== Files 22 22 Lines 1588 1592 +4 ========================================== + Hits 842 902 +60 + Misses 701 645 -56 Partials 45 45 ```

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