Added support for specifying units and nanos as input values

stockholm/money.py

@@ -12,6 +12,7 @@
 DEFAULT_MIN_DECIMALS = 2
 DEFAULT_MAX_DECIMALS = 9
 MAX_DECIMALS = 9
+UNITS_MAX_LENGTH = 18
 NANOS_LENGTH = 9
 
 HIGHEST_SUPPORTED_AMOUNT = "999999999999999999.999999999"
@@ -44,12 +45,37 @@ def __init__(
         amount: Optional[Union["Money", Decimal, int, float, str, object]] = None,
         currency: Optional[str] = None,
         is_cents: Optional[bool] = None,
+        units: Optional[int] = None,
+        nanos: Optional[int] = None,
         **kwargs: Any,
     ) -> None:
+        validate_amounts = []
+
+        if units is not None or nanos is not None:
+            try:
+                units = units or 0
+                nanos = nanos or 0
+                if (units > 0 and nanos < 0) or (units < 0 and nanos > 0):
+                    raise ValueError
+                units_str = str(units).lstrip("-")
+                nanos_str = str(nanos).lstrip("-").rjust(NANOS_LENGTH, "0")
+                if len(units_str) > UNITS_MAX_LENGTH:
+                    raise ValueError
+                if len(nanos_str) != NANOS_LENGTH:
+                    raise ValueError
+                sign = "-" if nanos < 0 or units < 0 else ""
+                units_amount = Decimal(f"{sign}{units_str}.{nanos_str}")
+                if amount is None:
+                    amount = units_amount
+                else:
+                    validate_amounts.append(units_amount)
+            except Exception:
+                raise ConversionError("Invalid values for units and nanos")
+
         if amount is None:
             raise ConversionError("Missing input values for monetary amount")
 
-        if isinstance(amount, Money) and currency is None and is_cents is None:
+        if isinstance(amount, Money) and currency is None and is_cents is None and units is None and nanos is None:
             object.__setattr__(self, "_amount", amount._amount)
             object.__setattr__(self, "_currency", amount._currency)
             return
@@ -146,6 +172,9 @@ def __init__(
         if output_amount == 0 and str(output_amount).startswith("-"):
             output_amount = Decimal(0)
 
+        if any([output_amount != a for a in validate_amounts]):
+            raise ConversionError("Input arguments does not match")
+
         object.__setattr__(self, "_amount", output_amount)
         object.__setattr__(self, "_currency", output_currency)
 

tests/test_init.py

@@ -1,3 +1,5 @@
+import pytest
+
 import stockholm
 
 
@@ -13,3 +15,8 @@ def test_init() -> None:
 def test_hash() -> None:
     m = stockholm.Money(0)
     assert hash(m)
+
+
+def test_empty_construct() -> None:
+    with pytest.raises(stockholm.ConversionError):
+        stockholm.Money()

tests/test_input_values.py

@@ -234,3 +234,45 @@ def __str__(self) -> str:
 
     with pytest.raises(ConversionError):
         Money(ThirdPartyMoney(None, output="USD USD"))
+
+
+def test_units_input() -> None:
+    assert Money(units=0, nanos=0) == 0
+    assert Money(units=0) == 0
+    assert Money(nanos=0) == 0
+    assert Money(units=0, nanos=1) == Money("0.000000001")
+    assert Money(nanos=2) == Money("0.000000002")
+    assert Money(nanos=-2) == Money("-0.000000002")
+    assert Money(units=4711) == Money(4711)
+    assert Money(units=-4711) == Money(-4711)
+    assert Money(units=1, nanos=750000000) == Money("1.75")
+    assert Money(units=0, nanos=100000000) == Money("0.1")
+    assert Money(units=-1, nanos=-750000000) == Money("-1.75")
+    assert Money(units=13381339, nanos=5005335) == Money("13381339.005005335")
+    assert Money(units=999999999999999999, nanos=999999999) == Money("999999999999999999.999999999")
+    assert Money(units=-999999999999999999, nanos=-999999999) == Money("-999999999999999999.999999999")
+
+    assert Money(units=1338, amount=1338) == Money(1338)
+    assert Money(units=1338, nanos=250000000, amount=Decimal("1338.25")) == Money("1338.25")
+    assert Money(units=1338, nanos=250000000, amount="1338.25 SEK") == Money("1338.25", currency="SEK")
+
+    with pytest.raises(ConversionError):
+        Money(units=-1, nanos=750000000)
+
+    with pytest.raises(ConversionError):
+        Money(units=1, nanos=-1)
+
+    with pytest.raises(ConversionError):
+        Money(nanos=1000000000)
+
+    with pytest.raises(ConversionError):
+        Money(units=1000000000000000000)
+
+    with pytest.raises(ConversionError):
+        Money(units=1338, amount=1337)
+
+    with pytest.raises(ConversionError):
+        Money(units=1338, nanos=250000000, amount=1338)
+
+    with pytest.raises(ConversionError):
+        Money(units=1338, nanos=250000000, amount="1338")