Changes to rm-refactor-overloaded-assets-operators

Related MR: !93 (merged)

package/test_tools/__private/utilities/decimal_converter.py

+from decimal import Decimal
+from typing import Union
+import warnings
+
+
+class DecimalConverter:
+    @classmethod
+    def convert(cls, amount: Union[int, float, str], precision: int) -> Decimal:
+        cls.__warn_if_precision_might_be_lost(amount, precision)
+
+        # We could not pass float variable directly to Decimal initializer as from the nature of floats it won't result
+        # in the exact decimal value. We need to convert float to string first like https://stackoverflow.com/a/18886013
+        # For example: `str(Decimal(0.1)) == '0.1000000000000000055511151231257827021181583404541015625'` is True
+        if isinstance(amount, float):
+            amount = repr(amount)
+
+        exponent = Decimal(10) ** (-1 * precision)
+        return Decimal(amount).quantize(exponent).normalize()
+
+    @staticmethod
+    def __warn_if_precision_might_be_lost(amount: Union[int, float], precision: int) -> None:
+        rounded_value = round(amount, precision)
+        acceptable_error = 0.1**10
+
+        if abs(amount - rounded_value) > acceptable_error:
+            warnings.warn(
+                f"Precision lost during asset creation.\n"
+                f"\n"
+                f"Asset with amount {amount} was requested, but this value was rounded to {rounded_value},\n"
+                f"because precision of this asset is {precision} ({pow(0.1, precision):.3f})."
+            )