util: format_satoshis_plain: remove TODO, hard-fail on float

Author: accumulator

electrum/commands.py

@@ -103,7 +103,7 @@ def satoshis(amount):
     return int(COIN*to_decimal(amount)) if amount is not None else None
 
 
-def format_satoshis(x: Union[float, int, Decimal, None]) -> Optional[str]:
+def format_satoshis(x: Union[int, Decimal, None]) -> Optional[str]:
     """
     input: satoshis as a Number
     output: str formatted as bitcoin amount

electrum/util.py

@@ -776,7 +776,7 @@ def chunks(items, size: int):
 
 
 def format_satoshis_plain(
-        x: Union[int, float, Decimal, str],  # amount in satoshis,
+        x: Union[int, Decimal, str],  # amount in satoshis,
         *,
         decimal_point: int = 8,  # how much to shift decimal point to left (default: sat->BTC)
         precision: int = 0,  # extra digits after satoshi precision (e.g. for msat)
@@ -786,8 +786,7 @@ def format_satoshis_plain(
     point and has no thousands separator"""
     if is_max_allowed and parse_max_spend(x):
         return f'max({x})'
-    assert isinstance(x, (int, float, Decimal)), f"{x!r} should be a number"
-    # TODO(ghost43) just hard-fail if x is a float. do we even use floats for money anywhere?
+    assert isinstance(x, (int, Decimal)), f"{x!r} should be an int or Decimal"
     x = to_decimal(x)
     scale_factor = pow(10, decimal_point)
     return "{:.{}f}".format(x / scale_factor, 8 + precision).rstrip('0').rstrip('.')