Fix to_rgba to recognise None

Author: has2k1

mizani/_colors/utils.py

@@ -61,7 +61,7 @@ def color_tuple_to_hex(t: RGBColor | RGBAColor) -> str:
 
 
 @overload
-def to_rgba(colors: ColorType, alpha: float) -> ColorType: ...
+def to_rgba(colors: ColorType | None, alpha: float) -> ColorType: ...
 
 
 @overload
@@ -83,7 +83,7 @@ def to_rgba(
 
 
 def to_rgba(
-    colors: Sequence[ColorType] | AnySeries | ColorType,
+    colors: Sequence[ColorType] | AnySeries | ColorType | None,
     alpha: float | Sequence[float] | AnySeries,
 ) -> Sequence[ColorType] | ColorType:
     """
@@ -121,6 +121,8 @@ def to_rgba(
             return (*colors, alpha)  # pyright: ignore[reportReturnType]
         else:
             return colors
+    elif colors is None:
+        return "none"
 
     if isinstance(alpha, (float, int)):
         return [to_rgba(c, alpha) for c in colors]  # pyright: ignore[reportCallIssue,reportArgumentType]

tests/colors/test_utils.py

@@ -30,6 +30,9 @@ def test_to_rgba():
     assert to_rgba("red", np.float64(0.5)) == "#FF000080"
     assert to_rgba("red", np.int64(1)) == "#FF0000FF"  # pyright: ignore[reportCallIssue,reportArgumentType]
 
+    assert to_rgba(None, 1) == "none"
+    assert to_rgba([None, None], 1) == ["none", "none"]  # pyright: ignore[reportCallIssue,reportArgumentType]
+
     with pytest.raises(ValueError):
         to_rgba("red", "0")  # pyright: ignore[reportCallIssue,reportArgumentType]