Replace assert statements with proper exception handling (#54)

Author: camille-bouvy-frequenz

RELEASE_NOTES.md

@@ -10,7 +10,7 @@
 
 ## New Features
 
-<!-- Here goes the main new features and examples or instructions on how to use them -->
+* Replace assert statements with proper exception handling
 
 ## Bug Fixes
 

src/frequenz/client/electricity_trading/_client.py

@@ -66,7 +66,8 @@ def validate_decimal_places(value: Decimal, decimal_places: int, name: str) -> N
         ValueError: If the value has more decimal places than allowed.
                     or the value is not a valid decimal number.
     """
-    assert decimal_places >= 0, "The decimal places must be a non-negative integer."
+    if decimal_places < 0:
+        raise ValueError("The decimal places must be a non-negative integer.")
 
     try:
         exponent = int(value.as_tuple().exponent)
@@ -287,7 +288,7 @@ async def stream_public_trades(
         return self._public_trades_streams[public_trade_filter].new_receiver()
 
     def validate_params(
-        # pylint: disable=too-many-arguments, too-many-positional-arguments
+        # pylint: disable=too-many-arguments, too-many-positional-arguments, too-many-branches
         self,
         price: Price | None | _Sentinel = NO_VALUE,
         quantity: Energy | None | _Sentinel = NO_VALUE,
@@ -359,9 +360,8 @@ def validate_params(
             if valid_until < datetime.now(timezone.utc):
                 raise ValueError("valid_until must be in the future")
         if order_type is not None:
-            assert order_type == OrderType.LIMIT, NotImplementedError(
-                "Currently only limit orders are supported"
-            )
+            if order_type != OrderType.LIMIT:
+                raise NotImplementedError("Currently only limit orders are supported.")
 
     async def create_gridpool_order(
         # pylint: disable=too-many-arguments, too-many-positional-arguments, too-many-locals

tests/test_validate_decimal_places.py

@@ -34,5 +34,5 @@ def test_invalid_inputs(self) -> None:
             validate_decimal_places(Decimal("NaN"), 2, "Test Value")
         with self.assertRaises(ValueError):
             validate_decimal_places(Decimal("Infinity"), 2, "Test Value")
-        with self.assertRaises(AssertionError):
+        with self.assertRaises(ValueError):
             validate_decimal_places(Decimal("123.45"), -1, "Test Value")