Fix item reformat during validation

[sebhub]

The ItemValidator._get_issues_tree() did write completely wrong links
back to the item, since the item variable was re-used as a loop
variable (now: parent). This bug did not manifest badly since
Item.set_links() had no auto_save decorator. Remove the superfluous
Item.set_links() and use the setter instead.

[stanislaw]

@sebhub thanks for catching this. This behavior of 1) finding issues and also 2) reformatting the item in the same method was something I wanted to raise later and refactor as a violation of SRP but I also managed to introduce a bug there 😞

I want to provide a test that ensures your change is included in the test harness. I will do it today or tomorrow max.

[sebhub]

I think the drop in code coverage due to the patch is harmless. The patch essentially removes a bit of code that was covered 100%. Since the overall coverage is below 100%, removing code with 100% code coverage drops the overall coverage since the ration between covered and uncovered code changes in favour of uncovered code.

[stanislaw]

I am not sure why you think that the coverage is the same. One of the tests I have written does @patch('doorstop.settings.REFORMAT', True) which makes the following branches to be executed (was not the case before).

        # Delay item save if reformatting 
        if settings.REFORMAT: 
            item.auto = False 

and

     if settings.REFORMAT: 
            log.debug("reformatting item %s...", item) 
            item.save() 

I guess, this is what makes CI to be green now.

[stanislaw]

But it is true that it is not clear, why the coverage in your changeset gets to be a bit less than 95%.

[sebhub]

Sorry for the confusion, my comment about the coverage was intended for my patch only and not the new tests. Lets say your code base has 10 lines, 5 lines are covered by tests, then your code coverage is 5 / (5 + 5) = 50%. If you remove one line of code which is covered but superfluous, then your coverage is 4 / (4 + 5) = 44%. I think this is what happened with my patch.

[stanislaw]

Yes, your explanation makes sense. Thank you.