Skip disabled constraints when visiting model; Fixes #173

[alwilson]

Traced the bounds processing to ModelVisitor and added a constraint enabled check.

Added a unittest that passes with this commit.

[mballance]

Hi @alwilson, thanks for taking the time to dig into this issue! If I understand correctly from issue #173, it seems that the core problem is that the bounds visitor isn't ignoring disabled constraints. If that is the case, I would recommend overriding the visit_constraint_block method from ModelVisitor (see below) in the bounds visitor class and only visit the base implementation if the constraint is enabled. https://github.com/fvutils/pyvsc/blob/743b6d3c3376dfa15feab91bfe454f5ee5a53eac/src/vsc/model/model_visitor.py#L106-L107

It should look something like:

class VariableBoundVisitor(ModelVisitor):
    # ...

    def visit_constraint_block(self, c : ConstraintBlockModel):
        if c.enabled:
            super().visit_constraint_block(c)
    # ...

This will allow other users of the ModelVisitor class to receive notifications of disabled and enabled constraint blocks, while blocking the bounds visitor from taking disabled constraints into account.

[alwilson]

Ah, reread your comment after going back. I need to play with git some more too. Haven't done much rebase/squash stuff from the command line before.

[mballance]

@alwilson, don't worry about squashing commits or rebasing -- this is a nice small change. If it were me, I'd just copy/paste the visit_constraint_block method over to the bounds visitor class, revert the changes in the model_visitor class, and call it it a day. Your call, though :-)

[alwilson]

Yeah, it does feel like a hole in my git knowledge... but I think even github will let you squash merge as well if you wanted. I recall seeing options for it before at least. Thanks for the feedback!

[mballance]

Many thanks, @alwilson!