COCOS-159 - Improve test coverage to 65%

[SammyOina]

What type of PR is this?

What does this do?

• New Features

  • Introduced comprehensive test cases for error handling in file operations and state machine functionalities.
  • Added new test cases for ATLS listener and connection functionalities, enhancing coverage for various scenarios.

• Bug Fixes

  • Improved error handling checks for nonexistent files in copy and checksum operations.

• Documentation

  • Updated the structure and naming conventions in the backend_info.json file for clarity and consistency.

• Tests

  • Enhanced test coverage with table-driven tests for various components, improving organization and readability.

Which issue(s) does this PR fix/relate to?

• Resolves Feature: Improve test coverage to exceed 65% #159

Have you included tests for your changes?

Did you document any new/modified feature?

Notes

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 65.42%. Comparing base (d5941ed) to head (acd0092).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #310      +/-   ##
==========================================
+ Coverage   62.36%   65.42%   +3.06%     
==========================================
  Files          54       53       -1     
  Lines        4320     4318       -2     
==========================================
+ Hits         2694     2825     +131     
+ Misses       1347     1218     -129     
+ Partials      279      275       -4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

---

🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests