Improve plugin Code Coverage

[prudhvigodithi]

Description

This is the 1st PR as part of this issue to improve the repo code coverage gradually.

Issues Resolved

Part of #612

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[prudhvigodithi]

FYI, I allowed the tests to run few times since yesterday and I get the following error.

{'detail': ErrorDetail(string='Rate limit reached. Please upload with the Codecov repository upload token to resolve issue. Expected available in 2831 seconds.', code='throttled')}

Let me add a Codecov token and update the test workflow to use the token for uploading the test report.
@bbarani @cwperks

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 37.37%. Comparing base (1d49ab4) to head (6fb1b11).

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #616      +/-   ##
============================================
+ Coverage     29.17%   37.37%   +8.20%     
- Complexity       98      133      +35     
============================================
  Files            22       22              
  Lines          1186     1188       +2     
  Branches        109      109              
============================================
+ Hits            346      444      +98     
+ Misses          819      707     -112     
- Partials         21       37      +16     

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

[prudhvigodithi]

Works now https://app.codecov.io/gh/opensearch-project/job-scheduler/pull/616 and I see the percentage is now 37.27% (from 29.17%).

@cwperks @joshpalis can you please check?
@bbarani

[cwperks]

Took a first pass. Thank you for adding missing test! This change looks good to me, just left some minor comments.

[prudhvigodithi]

Thanks @cwperks for reviewing the PR, initially I have to update the access modifiers to make sure those variables/methods are accessible for testing, I have reverted back and replaced to get the getters, can you review again?