Make UnaryPredicate JSON Serializable and Add Unit Tests

[Aniketsy]

#2522

This PR makes the UnaryPredicate class and its subclasses (IsNull, NotNull, IsNaN, NotNaN) JSON serializable using Pydantic

• Adds unit tests to verify JSON serialization for IsNull and NotNull

Please let me know if my approach or fix needs any improvements . I’m open to feedback and happy to make changes based on suggestions.
Thankyou !

[Aniketsy]

@Fokko please review these changes , when you get a chance.

[Aniketsy]

@Fokko While testing locally, I’m getting 15 test failures, but in the CI check, there’s only 1 test failing. Could you please help me understand what might be causing this difference?

[Fokko]

@Aniketsy Sure thing, I'm happy to. Could you share the output of the console?

[Aniketsy]

sure,

=================== short test summary info ===================
FAILED tests/expressions/test_expressions.py::test_reference - AttributeError: 'Reference' object has no attribute 'model_... FAILED tests/expressions/test_expressions.py::test_always_true - AttributeError: 'AlwaysTrue' object has no attribute 'model... FAILED tests/expressions/test_expressions.py::test_always_false - AttributeError: 'AlwaysFalse' object has no attribute 'mode...FAILED tests/expressions/test_expressions.py::test_serialize_is_null - AttributeError: 'IsNull' object has no attribute 'model_dum...
FAILED tests/expressions/test_expressions.py::test_serialize_not_null - AttributeError: 'NotNull' object has no attribute 'model_du...
FAILED tests/expressions/test_expressions.py::test_serialize_in - AttributeError: 'In' object has no attribute 'model_dump_json'FAILED tests/expressions/test_expressions.py::test_serialize_not_in - AttributeError: 'NotIn' object has no attribute 'model_dump...
FAILED tests/expressions/test_expressions.py::test_equal_to - AttributeError: 'EqualTo' object has no attribute 'model_du... FAILED tests/expressions/test_expressions.py::test_not_equal_to - AttributeError: 'NotEqualTo' object has no attribute 'model...FAILED tests/expressions/test_expressions.py::test_greater_than_or_equal_to - AttributeError: 'GreaterThanOrEqual' object has no attribut...
FAILED tests/expressions/test_expressions.py::test_greater_than - AttributeError: 'GreaterThan' object has no attribute 'mode...FAILED tests/expressions/test_expressions.py::test_less_than - AttributeError: 'LessThan' object has no attribute 'model_d... FAILED tests/expressions/test_expressions.py::test_less_than_or_equal - AttributeError: 'LessThanOrEqual' object has no attribute '...
FAILED tests/expressions/test_expressions.py::test_starts_with - AttributeError: 'StartsWith' object has no attribute 'model... FAILED tests/expressions/test_expressions.py::test_not_starts_with - AttributeError: 'NotStartsWith' object has no attribute 'mo...
=============== 15 failed, 145 passed in 1.65s 

[Fokko]

Nice one @Aniketsy! This looks good to me 👍

[Aniketsy]

@Fokko Thanks!