fix(filter): keep numeric operands exact instead of coercing to float

float() rounds any integer past 2**53 and flattens a Decimal, so
{"token_count": {"gt": 9007199254740993}} silently compared against
9007199254740992 — a different row set than the client asked for.

_coerce_numeric passes already-numeric operands through untouched and
only parses strings, trying int() before float() so "5" stays exact
while "5.5" still parses. bool narrows to int: it is an int subclass,
but binding it as a boolean against a numeric column produces SQL
Postgres has no operator for.

Not coerced to the column's own type: int(5.5) would turn
{"token_count": {"lt": 5.5}} into `lt 5`, changing which rows match.

Also fixes a vacuous assertion in test_dict_on_jsonb_column_still_works.
It checked for "internal_metadata" in the whole statement, but that name
is in the SELECT projection either way, so the test passed even when no
WHERE clause was applied. Now asserts on stmt.whereclause and that the
filter payload is actually bound.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/utils/filter.py

@@ -79,6 +79,35 @@ SCALAR_OPERAND_TYPES = (
 )
 
 
+def _coerce_numeric(op_value: Any) -> int | float | Decimal:
+    """Validate a numeric operand without losing precision.
+
+    float() rounds an int past 2**53 and flattens a Decimal, so an operand that
+    is already numeric is passed through untouched and only strings are parsed.
+    int() is tried before float() so "5" stays exact while "5.5" still parses.
+    bool is narrowed to int: it is an int subclass, but binding it as a boolean
+    against a numeric column produces SQL Postgres has no operator for.
+
+    Args:
+        op_value: The operand to validate.
+
+    Returns:
+        The operand as an exact numeric value.
+
+    Raises:
+        ValueError, TypeError: If the operand is not numeric. Callers convert
+            these to FilterError.
+    """
+    if isinstance(op_value, bool):
+        return int(op_value)
+    if isinstance(op_value, int | float | Decimal):
+        return op_value
+    try:
+        return int(op_value)
+    except ValueError:
+        return float(op_value)
+
+
 def _require_bindable_operand(
     column_name: str, op_value: Any, operator: str = ""
 ) -> None:
@@ -670,7 +699,7 @@ def _build_comparison_conditions(
             # number. On a text column, `ne` is a string comparison.
             if operator in NUMERIC_OPERATORS and is_numeric_column:
                 try:
-                    casted_value = float(op_value)
+                    casted_value = _coerce_numeric(op_value)
                 except (TypeError, ValueError):
                     raise FilterError(
                         f"Invalid numeric value: {op_value}. Expected a number, got {type(op_value).__name__}"

tests/utils/test_filter.py

@@ -35,7 +35,34 @@ def test_known_operator_dict_on_scalar_column_still_works():
 
 def test_dict_on_jsonb_column_still_works():
     stmt = apply_filter(select(Document), Document, {"metadata": {"kind": "note"}})
-    assert "internal_metadata" in str(stmt)
+    # Assert on the WHERE clause specifically: internal_metadata is in the
+    # SELECT projection either way, so checking the whole statement passes even
+    # when no condition was applied at all.
+    assert stmt.whereclause is not None
+    assert "internal_metadata" in str(stmt.whereclause)
+    compiled = stmt.compile(dialect=postgresql.dialect())
+    assert {"kind": "note"} in [bind.value for bind in compiled.binds.values()]
+
+
+def test_numeric_operand_keeps_integer_precision():
+    """float() rounds anything past 2**53, silently shifting the comparison."""
+    big = 2**53 + 1
+    stmt = apply_filter(select(Message), Message, {"token_count": {"gt": big}})
+    compiled = stmt.compile(dialect=postgresql.dialect())
+    assert big in [bind.value for bind in compiled.binds.values()]
+
+
+def test_fractional_operand_on_integer_column_is_not_truncated():
+    """Coercing to the column's int type would turn `lt 5.5` into `lt 5`."""
+    stmt = apply_filter(select(Message), Message, {"token_count": {"lt": 5.5}})
+    compiled = stmt.compile(dialect=postgresql.dialect())
+    assert 5.5 in [bind.value for bind in compiled.binds.values()]
+
+
+def test_numeric_string_operand_stays_exact():
+    stmt = apply_filter(select(Message), Message, {"token_count": {"gt": "5"}})
+    compiled = stmt.compile(dialect=postgresql.dialect())
+    assert 5 in [bind.value for bind in compiled.binds.values()]
 
 
 def test_ne_none_on_scalar_column_is_not_null():