From 88cd4e3f67f8a72d99afe0d2e2e87f9f08715a3c Mon Sep 17 00:00:00 2001
From: Ayush Kumar Saha <225407166+AP24110011695@users.noreply.github.com>
Date: Thu, 5 Nov 2026 00:32:26 +0530
Subject: [PATCH] fix(expressions): reject non-finite floats on conversion to
 Decimal

float('inf') is a valid float/double literal, but converting it to a
Decimal type crashed with a bare decimal.InvalidOperation instead of the
ValueError every other impossible conversion in this module raises.
NaN is already rejected at literal construction; infinity now gets a
clean, consistent domain error.

Signed-off-by: Ayush Kumar Saha <225407166+AP24110011695@users.noreply.github.com>
---
 pyiceberg/expressions/literals.py  |  6 +++++-
 tests/expressions/test_literals.py | 16 ++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/pyiceberg/expressions/literals.py b/pyiceberg/expressions/literals.py
index b91e404627..99f6948b63 100644
--- a/pyiceberg/expressions/literals.py
+++ b/pyiceberg/expressions/literals.py
@@ -26,7 +26,7 @@
 from datetime import date, datetime, time
 from decimal import ROUND_HALF_UP, Decimal
 from functools import singledispatchmethod
-from math import isnan
+from math import isfinite, isnan
 from typing import Any, Generic
 from uuid import UUID
 
@@ -414,6 +414,8 @@ def _(self, _: DoubleType) -> Literal[float]:
 
     @to.register(DecimalType)
     def _(self, type_var: DecimalType) -> Literal[Decimal]:
+        if not isfinite(self.value):
+            raise ValueError(f"Could not convert {self.value} into a {type_var}, value is not finite")
         return DecimalLiteral(Decimal(self.value).quantize(Decimal((0, (1,), -type_var.scale)), rounding=ROUND_HALF_UP))
 
 
@@ -439,6 +441,8 @@ def _(self, _: FloatType) -> Literal[float]:
 
     @to.register(DecimalType)
     def _(self, type_var: DecimalType) -> Literal[Decimal]:
+        if not isfinite(self.value):
+            raise ValueError(f"Could not convert {self.value} into a {type_var}, value is not finite")
         return DecimalLiteral(Decimal(self.value).quantize(Decimal((0, (1,), -type_var.scale)), rounding=ROUND_HALF_UP))
 
 
diff --git a/tests/expressions/test_literals.py b/tests/expressions/test_literals.py
index a7f1c2d43d..dcdcd62556 100644
--- a/tests/expressions/test_literals.py
+++ b/tests/expressions/test_literals.py
@@ -277,6 +277,22 @@ def test_double_to_decimal_conversion(decimal_type: DecimalType, decimal_value:
     assert lit.to(decimal_type).value.as_tuple() == Decimal(decimal_value).as_tuple()  # type: ignore
 
 
+def test_float_to_decimal_conversion_with_infinity() -> None:
+    lit = FloatLiteral(float("inf"))
+
+    with pytest.raises(ValueError) as e:
+        _ = lit.to(DecimalType(9, 2))
+    assert "Could not convert inf into a decimal(9, 2), value is not finite" in str(e.value)
+
+
+def test_double_to_decimal_conversion_with_infinity() -> None:
+    lit = DoubleLiteral(float("inf"))
+
+    with pytest.raises(ValueError) as e:
+        _ = lit.to(DecimalType(9, 2))
+    assert "Could not convert inf into a decimal(9, 2), value is not finite" in str(e.value)
+
+
 def test_decimal_to_decimal_conversion() -> None:
     lit = literal(Decimal("34.11").quantize(Decimal(".01")))