Fix a bug in database compare.

[mgjarrett]

Description

---

There's a line in compareDB3.py that tries to call a method that doesn't exist, DiffResults.add()

This has been around for a long time, but we have somehow just coincidentally not been hitting it.

Also, another call to addDiff needed to be updated to pass numpy.inf as a scalar instead of a list.

Checklist

• This PR has only one purpose or idea.
• Tests have been added/updated to verify that the new/changed code works.

• The code style follows good practices.
• The commit message(s) follow good practices.

• The release notes (location doc/release/0.X.rst) are up-to-date with any bug fixes or new features.
• The documentation is still up-to-date in the doc folder.
• The dependencies are still up-to-date in setup.py.

[onufer]

can you describe in the PR why the brackets were removed?

[mgjarrett]

Yes, addDiff expects three floats based on the type hints:

armi/armi/bookkeeping/db/compareDB3.py

Lines 114 to 116 in 199d250

	def addDiff(
	self, compType: str, paramName: str, absMean: float, mean: float, absMax: float
	) -> None:

And it compares these three parameters with >, which doesn't work on a list.

[mgjarrett]

I was able to add a unit test for one of the bad function calls.

For the second one, where the name of the function was wrong (add() instead of addDiff()), I have not been able to get the unit test to hit the line. To get here, we have to read some data src from an HDF5 dataset, iterate throught src.tolist() which ostensibly creates regular python lists, and then check if any of the items created by tolist() are numpy.ndarray instead of a regular list. I don't know how to make this happen, and I'm not sure how I happened upon it yesterday. For now I'll settle for leaving the line uncovered; I know the fix works because I tried it on my in-use case that was failing.