Changed is_defined into a ThingClass property and improved its documentation.

[jesper-friis]

Description:

Also added tests.

Closes #563

Type of change:

• Bug fix.
• New feature.
• Documentation update.
• Test update.

Checklist:

This checklist can be used as a help for the reviewer.

• Is the code easy to read and understand?
• Are comments for humans to read, not computers to disregard?
• Does a new feature has an accompanying new test (in the CI or unit testing schemes)?
• Has the documentation been updated as necessary?
• Does this close the issue?
• Is the change limited to the issue?
• Are errors handled for all outcomes?
• Does the new feature provide new restrictions on dependencies, and if so is this documented?

Comments:

[codecov]

Codecov Report

Merging #597 (39b63f5) into master (7b1c9c4) will increase coverage by 0.19%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master     #597      +/-   ##
==========================================
+ Coverage   67.28%   67.47%   +0.19%     
==========================================
  Files          16       16              
  Lines        3127     3130       +3     
==========================================
+ Hits         2104     2112       +8     
+ Misses       1023     1018       -5     

Impacted Files	Coverage Δ
ontopy/ontology.py	71.74% <0.00%> (-0.41%)	⬇️
ontopy/graph.py	67.85% <100.00%> (ø)
ontopy/patch.py	61.65% <100.00%> (+6.69%)	⬆️

[francescalb]

I really think this is a bad idea. We have implemented pytest and should use that.

[jesper-friis]

I don't think implementing the test as a script defeat pytest in any way. It is picked up and runs nicely with pytest.

[francescalb]

This is a very vague title. There is a whole folder called onopy_tests. Shold this go in there? The title of the file should be more specific, and I also think the tests should be made as functions that also are called according to what they test.

[jesper-friis]

I updated the title and renamed the test to ontopy_tests/test_patch.py