Enhance MET testing infrastructure to compute code coverage statistics

Describe the New Feature

The Australian BOM requires a certain test coverage percentage in order for software to be run operationally. This requirement applies to both METplus (python requirement of 90+% coverage) and MET (unknown coverage requirements). This task is to setup code coverage computation for MET and consists of multiple steps.

Identify which toolchain to use (consider the GNU gcov utility).
Compile MET with coverage enabled.
Run full set of MET unit tests and write coverage information.
Produce a report to quantify the coverage.
Quantify the impact to runtime performance.
Automate the computation of code coverage via GHA.

Acceptance Testing

List input data types and sources. Describe tests required for new functionality.

Time Estimate

Estimate the amount of work required here. Issues should represent approximately 1 to 3 days of work.

Sub-Issues

Consider breaking the new feature down into sub-issues. Not sure yet.

Relevant Deadlines

List relevant project deadlines here or state NONE.

Funding Source

Define the source of funding and account keys here or state NONE.

Define the Metadata

Assignee

[x] Select engineer(s) or no engineer required
[ ] Select scientist(s) or no scientist required

Labels

[x] Select component(s)
[x] Select priority
[x] Select requestor(s)

Projects and Milestone

[x] Select Repository and/or Organization level Project(s) or add alert: NEED CYCLE ASSIGNMENT label
[x] Select Milestone as the next official version or Future Versions

Define Related Issue(s)

Consider the impact to the other METplus components.

[x] METplus, MET, METdataio, METviewer, METexpress, METcalcpy, METplotpy Likely no impacts.

New Feature Checklist

See the METplus Workflow for details.

[ ] Complete the issue definition above, including the Time Estimate and Funding source.
[ ] Fork this repository or create a branch of develop. Branch name: feature_<Issue Number>_<Description>
[ ] Complete the development and test your changes.
[ ] Add/update log messages for easier debugging.
[ ] Add/update unit tests.
[ ] Add/update documentation.
[ ] Push local changes to GitHub.
[ ] Submit a pull request to merge into develop. Pull request: feature <Issue Number> <Description>
[ ] Define the pull request metadata, as permissions allow. Select: Reviewer(s) and Development issues Select: Repository level development cycle Project for the next official release Select: Milestone as the next official version
[ ] Iterate until the reviewer(s) accept and merge your changes.
[ ] Delete your fork or branch.
[ ] Close this issue.

dtcenter / MET