TST: stricter monotonicity/uniqueness tests (part 2)

[topper-123]

• xref TST: stricter monotonicity/uniqueness tests #23256
• tests added / passed
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

Continuation of #23256.

By making the uniqueness tests stricter (i.e. testing for actual True/False rather than truthy/Falsy values) I think we get better ensurance that some PR doesn't accidentally turn a property into a method or that the property doesn't accidentally returns a non-boolean return value.

[pep8speaks]

Hello @topper-123! Thanks for submitting the PR.

• There are no PEP8 issues in the file pandas/tests/indexes/common.py !

• There are no PEP8 issues in the file pandas/tests/indexes/interval/test_interval.py !

• There are no PEP8 issues in the file pandas/tests/indexes/multi/test_duplicates.py !

• There are no PEP8 issues in the file pandas/tests/indexes/multi/test_integrity.py !

• There are no PEP8 issues in the file pandas/tests/indexing/test_loc.py !

• There are no PEP8 issues in the file pandas/tests/series/indexing/test_indexing.py !

• There are no PEP8 issues in the file pandas/tests/series/test_duplicates.py !

• There are no PEP8 issues in the file pandas/tests/test_algos.py !

• There are no PEP8 issues in the file pandas/tests/test_multilevel.py !

• There are no PEP8 issues in the file pandas/tests/util/test_hashing.py !

[TomAugspurger]

Looks like some related test failures though.

[codecov]

Codecov Report

Merging #23294 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #23294   +/-   ##
=======================================
  Coverage   92.22%   92.22%           
=======================================
  Files         169      169           
  Lines       50897    50897           
=======================================
  Hits        46940    46940           
  Misses       3957     3957

Flag	Coverage Δ
#multiple	90.65% <ø> (ø)	⬆️
#single	42.29% <ø> (ø)	⬆️

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[topper-123]

The failure issue was that Index.hasnans sometimes returns a python boolen and sometimes a numpy boolean.

As this PR mainly concerns itself with is_monotonoc* and is_unique, I've simply removed the few changes to hasnans tests from this PR. I will later submit a seperate PR regarding hasnans, so as to keep things clean.

[jreback]

thanks!