TST: fix Decimal constructor xfail (#54338)

* TST: fix Decimal constructor xfail

* mypy fixup

Author: jbrockmendel

pandas/tests/extension/decimal/array.py

@@ -12,6 +12,7 @@
 from pandas.core.dtypes.common import (
     is_dtype_equal,
     is_float,
+    is_integer,
     pandas_dtype,
 )
 
@@ -71,11 +72,14 @@ class DecimalArray(OpsMixin, ExtensionScalarOpsMixin, ExtensionArray):
 
     def __init__(self, values, dtype=None, copy=False, context=None) -> None:
         for i, val in enumerate(values):
-            if is_float(val):
+            if is_float(val) or is_integer(val):
                 if np.isnan(val):
                     values[i] = DecimalDtype.na_value
                 else:
-                    values[i] = DecimalDtype.type(val)
+                    # error: Argument 1 has incompatible type "float | int |
+                    # integer[Any]"; expected "Decimal | float | str | tuple[int,
+                    # Sequence[int], int]"
+                    values[i] = DecimalDtype.type(val)  # type: ignore[arg-type]
             elif not isinstance(val, decimal.Decimal):
                 raise TypeError("All values must be of type " + str(decimal.Decimal))
         values = np.asarray(values, dtype=object)

pandas/tests/extension/decimal/test_decimal.py

@@ -267,20 +267,16 @@ def test_series_repr(self, data):
         assert "Decimal: " in repr(ser)
 
 
-@pytest.mark.xfail(
-    reason=(
-        "DecimalArray constructor raises bc _from_sequence wants Decimals, not ints."
-        "Easy to fix, just need to do it."
-    ),
-    raises=TypeError,
-)
-def test_series_constructor_coerce_data_to_extension_dtype_raises():
-    xpr = (
-        "Cannot cast data to extension dtype 'decimal'. Pass the "
-        "extension array directly."
+def test_series_constructor_coerce_data_to_extension_dtype():
+    dtype = DecimalDtype()
+    ser = pd.Series([0, 1, 2], dtype=dtype)
+
+    arr = DecimalArray(
+        [decimal.Decimal(0), decimal.Decimal(1), decimal.Decimal(2)],
+        dtype=dtype,
     )
-    with pytest.raises(ValueError, match=xpr):
-        pd.Series([0, 1, 2], dtype=DecimalDtype())
+    exp = pd.Series(arr)
+    tm.assert_series_equal(ser, exp)
 
 
 def test_series_constructor_with_dtype():