fix(expressions): reject fractional strings converting to int/long

pyiceberg/expressions/literals.py

@@ -595,7 +595,7 @@ def _(self, type_var: IntegerType) -> Literal[int]:
                 return IntAboveMax()
             elif IntegerType.min > number:
                 return IntBelowMin()
-            return LongLiteral(int(number))
+            return LongLiteral(_to_integral(number, type_var))
         except (ArithmeticError, OverflowError, ValueError) as e:
             raise ValueError(f"Could not convert {self.value} into a {type_var}") from e
 
@@ -608,7 +608,7 @@ def _(self, type_var: LongType) -> Literal[int]:
             elif LongType.min > long_value:
                 return LongBelowMin()
             else:
-                return LongLiteral(int(long_value))
+                return LongLiteral(_to_integral(long_value, type_var))
         except (ArithmeticError, OverflowError, TypeError, ValueError) as e:
             raise ValueError(f"Could not convert {self.value} into a {type_var}") from e
 

tests/expressions/test_literals.py

@@ -325,9 +325,6 @@ def test_string_literal() -> None:
     pi_string_lit = StringLiteral("3.141")
     pi_double_lit = literal(3.141).to(DoubleType())
 
-    assert literal("3.141").to(IntegerType()) == literal(3)
-    assert literal("3.141").to(LongType()) == literal(3)
-
     assert sqrt2 != pi
     assert pi != pi_double_lit
     assert pi == pi_string_lit
@@ -946,6 +943,14 @@ def test_fractional_decimal_to_integral_type_raises() -> None:
                 _ = DecimalLiteral(Decimal(value)).to(target_type)
 
 
+def test_fractional_string_to_integral_type_raises() -> None:
+    # Rounding would change the predicate, e.g. x < "2.6" would become x < 2 and drop x = 2
+    for target_type in [IntegerType(), LongType()]:
+        for value in ["2.5", "2.6", "-2.5", "0.1"]:
+            with pytest.raises(ValueError, match=f"Could not convert {value} into a {target_type}"):
+                _ = literal(value).to(target_type)
+
+
 def test_integral_decimal_to_integral_type() -> None:
     # A decimal literal without a fractional part, such as 2.0, still converts exactly
     for target_type in [IntegerType(), LongType()]: