fix: serialize AlwaysTrue/AlwaysFalse as boolean literals

Author: geruh

pyiceberg/expressions/__init__.py

@@ -370,10 +370,10 @@ def __getnewargs__(self) -> tuple[BooleanExpression]:
         return (self.child,)
 
 
-class AlwaysTrue(BooleanExpression, Singleton, IcebergRootModel[str]):
+class AlwaysTrue(BooleanExpression, Singleton, IcebergRootModel[bool]):
     """TRUE expression."""
 
-    root: str = "true"
+    root: bool = True
 
     def __invert__(self) -> AlwaysFalse:
         """Transform the Expression into its negated version."""
@@ -388,10 +388,10 @@ def __repr__(self) -> str:
         return "AlwaysTrue()"
 
 
-class AlwaysFalse(BooleanExpression, Singleton, IcebergRootModel[str]):
+class AlwaysFalse(BooleanExpression, Singleton, IcebergRootModel[bool]):
     """FALSE expression."""
 
-    root: str = "false"
+    root: bool = False
 
     def __invert__(self) -> AlwaysTrue:
         """Transform the Expression into its negated version."""

tests/expressions/test_expressions.py

@@ -770,7 +770,7 @@ def test_not_json_serialization_and_deserialization() -> None:
 
 def test_always_true() -> None:
     always_true = AlwaysTrue()
-    assert always_true.model_dump_json() == '"true"'
+    assert always_true.model_dump_json() == "true"
     assert str(always_true) == "AlwaysTrue()"
     assert repr(always_true) == "AlwaysTrue()"
     assert always_true == eval(repr(always_true))
@@ -779,7 +779,7 @@ def test_always_true() -> None:
 
 def test_always_false() -> None:
     always_false = AlwaysFalse()
-    assert always_false.model_dump_json() == '"false"'
+    assert always_false.model_dump_json() == "false"
     assert str(always_false) == "AlwaysFalse()"
     assert repr(always_false) == "AlwaysFalse()"
     assert always_false == eval(repr(always_false))