Use ClassId name in prettifiedName if canonical name is null

[dtim]

Description

Anonymous classes do not have canonical names, It makes ClassId::canonicalName property fail with an exception. ClassId::prettifiedName fails for anonymous classes as well.

This fix changes the call to exception-throwing ClassId::canonicalName in prettifiedName with an explicit call to jClass::canonicalName which returns a nullable value. If the class has no canonical name, ClassId::name is used instead.

Fixes #459

Type of Change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Automated Testing

Existing tests should not fail.

Manual Scenario

Run contest estimator with methodFilter = "com.google.common.base.CaseFormat.*" and projectFilter = null.

Without this fix, errors like this will be presented:

 public void testValues_errors()
     {
        // Couldn't generate some tests. List of errors:
        // 
        // 1 occurrences of:
        // ClassId com.google.common.base.CaseFormat$1 does not have canonical name
        
    }

With the fix, no these errors will be produced (many other errors will probably be generated instead, as there are related bugs and limitations in enum processing, both in engine and codegen).

Checklist (remove irrelevant options):

• The change followed the style guidelines of the UTBot project
• Self-review of the code is passed
• The change contains enough commentaries, particularly in hard-to-understand areas
• New documentation is provided or existed one is altered
• No new warnings
• Tests that prove my change is effective
• All tests pass locally with my changes

[Damtev]

LGTM, but could you please extend the existing documentation (in what cases do we return just a ClassId.name)?

[dtim]

LGTM, but could you please extend the existing documentation (in what cases do we return just a ClassId.name)?

Done, thank you.