Description

ToString for lists (as well as for other inheritors of AbstractCollection didn't work since it's too complicated for the engine because of StringBuilder usage somewhere inside of it. I've decided to make a temporary solution, implementing this method with makeSymbolic mechanism -- the method should return an unbounded symbolic variable, that will allow us to continue the analysis (in contrast to the executeConcretely). Later, the concrete execution will find the right result for such execution, if it's required.

My suggestion is based on thoughts that people usually use toString on collections just for logging, showing or something like that, and the resulting line won't present in the path constraints. It's not 100% true, but in many cases, it will work.

Fixes #391

Type of Change

• Breaking change. toString without concrete executor works differently now for the inheritors of the AbstractCollection and HashSet

How Has This Been Tested?

Automated Testing

Added test in the corresponding package.

Manual Scenario

Same test, since it is only about toString method on any collection.

Checklist:

• 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
• No new warnings
• Tests that prove my change is effective
• All tests pass locally with my changes