Fix deprecation warning for truth value of an empty array [all tests ci]

[ctuguinay]

Fixes deprecation warning which arose in the azfp6 parser when checking valid parameters for temperature and tilt which was discovered in #1444:

Warning: The truth value of an empty array is ambiguous. Returning False, but in future this will result in an error. Use array.size > 0 to check that an array is not empty.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.32%. Comparing base (9f56124) to head (2e24e75).
Report is 186 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1450      +/-   ##
==========================================
+ Coverage   83.52%   85.32%   +1.80%     
==========================================
  Files          64       72       +8     
  Lines        5686     6583     +897     
==========================================
+ Hits         4749     5617     +868     
- Misses        937      966      +29     

Flag	Coverage Δ
unittests	85.32% <100.00%> (+1.80%)	⬆️

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[ctuguinay]

@leewujung This one is ready for review

[leewujung]

Since the one fixed is under parse_azfp6 which I think came from parse_azfp, I took a look there too and found the same _test_valid_params function there. This repetition is not supposed to be like this, but it is part of the unfinished #1301 and #1323. I'll push the same change as what you had for the azfp counterpart.

Also, I think the condition you tested for should output False? Since in this case, self.parameters[[] does not contain valid parameters? I'll push this change too and you could review.

[leewujung]

Actually, I was wrong, the parameters were saved differently in azfp and azfp6 format.
In azfp, if some parameters are missing, the values are set to 0.
In azfp6, if some parameters are missing, the values simply do not exist.
So @ctuguinay you changes made sense.

The only thing I changed was to go from True to False.

I am not sure if the below block is still needed -- seems better to remove?

if all([np.isclose(self.parameters[p], 0) for p in params]):
    return False

[leewujung]

Oops I messed this up. Will look again tomorrow.

[leewujung]

Ok, turns out that this is a bug from #1323 that the parameter checking was somehow moved to before the XML part of the file is parsed in ParseAZFP6 (it was the correct order in ParseAZFP). With that fixed, the scenario that produces the warning should never happen.

Let me know what you think.

[ctuguinay]

@leewujung Ah good catch. I double checked and in no case do we end up with an empty array. I'll squash merge this now.