Develop unittest fixes
Due to the unknown failure of the pipeline, I found that the unit tests were not run on the GitLab pipeline because
^tests$ was added in .Rbuildignore. Therefore,
- R -e 'covr::package_coverage()' in the .gitlab-ci.yml couldn't work because there was no unit test. I tried to remove
^tests$ from .Rbuildignore, but the pipeline failed to run testthat.R for unknown reasons. I don't know why but the same setting works in startR. So now,
^tests$ is still in .Rbuildignore, and we need to run the unit tests on our own everytime after the development.
The branch includes the fixes for the errors shown in unit tests (but I didn't realize since the tests were not run all the time.) Since it's too late for the new release, we have to wait for the next time. Sorry for the trouble.