Merge pull request #5092 from domsammut/master

[bug] Round Decimal to 9 places to support DynamoDB constraints

changelog/5092.bugfix.rst

@@ -0,0 +1 @@
+DynamoDB tracker store decimal values will now be rounded on save. Previously values exceeding 38 digits caused an unhandled error.

rasa/core/utils.py

@@ -458,14 +458,15 @@ def handler(fut: Future) -> None:
     return handler
 
 
-def replace_floats_with_decimals(obj: Union[List, Dict]) -> Any:
+def replace_floats_with_decimals(obj: Union[List, Dict], round_digits: int = 9) -> Any:
     """
     Utility method to recursively walk a dictionary or list converting all `float` to `Decimal` as required by DynamoDb.
 
     Args:
         obj: A `List` or `Dict` object.
+        round_digits: A int value to set the rounding precision of Decimal values.
 
-    Returns: An object with all matching values and `float` type replaced by `Decimal`.
+    Returns: An object with all matching values and `float` types replaced by `Decimal`s rounded to `round_digits` decimal places.
 
     """
     if isinstance(obj, list):
@@ -477,7 +478,7 @@ def replace_floats_with_decimals(obj: Union[List, Dict]) -> Any:
             obj[j] = replace_floats_with_decimals(obj[j])
         return obj
     elif isinstance(obj, float):
-        return Decimal(obj)
+        return round(Decimal(obj), round_digits)
     else:
         return obj
 

tests/core/test_utils.py

@@ -98,6 +98,7 @@ def test_float_conversion_to_decimal():
     d = {
         "int": -1,
         "float": 2.1,
+        "float_round": 1579507733.1107571125030517578125,
         "list": ["one", "two"],
         "list_of_floats": [1.0, -2.1, 3.2],
         "nested_dict_with_floats": {"list_with_floats": [4.5, -5.6], "float": 6.7},
@@ -106,6 +107,7 @@ def test_float_conversion_to_decimal():
 
     assert isinstance(d_replaced["int"], int)
     assert isinstance(d_replaced["float"], Decimal)
+    assert d_replaced["float_round"] == Decimal("1579507733.110757113")
     for t in d_replaced["list"]:
         assert isinstance(t, str)
     for f in d_replaced["list_of_floats"]: