Fix JSON encoding of large integers

src/celpy/adapter.py

@@ -43,23 +43,26 @@ class CELJSONEncoder(json.JSONEncoder):
 
     This is **not** a reversible transformation. Some things are coerced to strings
     without any more detailed type marker.
-    Specifically timestamps, durations, and bytes.
+    Specifically timestamps, durations, bytes, and integers outside the interoperable range.
     """
 
     @staticmethod
     def to_python(
         cel_object: celtypes.Value,
-    ) -> Union[celtypes.Value, List[Any], Dict[Any, Any], bool]:
+    ) -> Union[celtypes.Value, List[Any], Dict[Any, Any], bool, str]:
         """Recursive walk through the CEL object, replacing :py:class:`celpy.celtypes.BoolType` with native ``bool`` instances.
         This lets the :py:mod:`json` module correctly represent the obects
         with JSON ``true`` and ``false``.
 
         This will also replace :py:class:`celpy.celtypes.ListType` and :py:class:`celpy.celtypes.MapType` with native ``list`` and ``dict``.
+        CEL integers outside ``-(2**53 - 1)`` to ``2**53 - 1`` become decimal strings.
         All other CEL objects will be left intact. This creates an intermediate hybrid
         beast that's not quite a :py:class:`celpy.celtypes.Value` because a few things have been replaced.
         """
         if isinstance(cel_object, celtypes.BoolType):
             return True if cel_object else False
+        elif isinstance(cel_object, (celtypes.IntType, celtypes.UintType)):
+            return str(cel_object) if abs(cel_object) > 2**53 - 1 else cel_object
         elif isinstance(cel_object, celtypes.ListType):
             return [CELJSONEncoder.to_python(item) for item in cel_object]
         elif isinstance(cel_object, celtypes.MapType):
@@ -72,7 +75,7 @@ def to_python(
 
     def encode(self, cel_object: celtypes.Value) -> str:
         """
-        Override built-in encode to create proper Python ``bool`` objects.
+        Override built-in encode to convert booleans and large integers.
         """
         return super().encode(CELJSONEncoder.to_python(cel_object))
 

tests/test_package.py

@@ -96,6 +96,31 @@ def test_encoder():
     )
 
 
+@pytest.mark.parametrize(
+    "cel_value, expected",
+    [
+        (celpy.celtypes.IntType(-2**63), '"-9223372036854775808"'),
+        (celpy.celtypes.IntType(-(2**53 + 1)), '"-9007199254740993"'),
+        (celpy.celtypes.IntType(-2**53), '"-9007199254740992"'),
+        (celpy.celtypes.IntType(-(2**53 - 1)), "-9007199254740991"),
+        (celpy.celtypes.IntType(2**53 - 1), "9007199254740991"),
+        (celpy.celtypes.IntType(2**53), '"9007199254740992"'),
+        (celpy.celtypes.IntType(2**53 + 1), '"9007199254740993"'),
+        (celpy.celtypes.IntType(2**63 - 1), '"9223372036854775807"'),
+        (celpy.celtypes.UintType(2**53 - 1), "9007199254740991"),
+        (celpy.celtypes.UintType(2**53), '"9007199254740992"'),
+        (celpy.celtypes.UintType(2**53 + 1), '"9007199254740993"'),
+        (celpy.celtypes.UintType(2**64 - 1), '"18446744073709551615"'),
+    ],
+)
+def test_encoder_integer_range(cel_value, expected):
+    assert json.dumps(cel_value, cls=celpy.CELJSONEncoder) == expected
+    cel_obj = celpy.celtypes.MapType(
+        {celpy.celtypes.StringType("numbers"): celpy.celtypes.ListType([cel_value])}
+    )
+    assert json.dumps(cel_obj, cls=celpy.CELJSONEncoder) == f'{{"numbers": [{expected}]}}'
+
+
 def test_encoder_unknown():
     cel_obj = sentinel.no_json
     with pytest.raises(TypeError):