Fix mypy errors in scaling module

Author: FabianHofmann

linopy/scaling.py

@@ -126,7 +126,10 @@ def resolve_options(scale: bool | str | ScaleOptions | None) -> ScaleOptions:
     if scale is True:
         return ScaleOptions()
     if isinstance(scale, str):
-        return ScaleOptions(method=scale)
+        if scale not in ("row-max", "row-l2"):
+            msg = f"Invalid scale method: {scale!r}. Must be 'row-max' or 'row-l2'."
+            raise ValueError(msg)
+        return ScaleOptions(method=scale)  # type: ignore[arg-type]
     if isinstance(scale, ScaleOptions):
         return scale
 

test/test_scaling.py

@@ -23,6 +23,7 @@ def test_row_scaling_and_dual_unscale() -> None:
 
     assert np.isclose(ctx.row_scale[0], 0.25)
     assert np.isclose(ctx.row_scale[1], 2.0)
+    assert M.A is not None
     A = np.asarray(M.A.todense())
     # Row 0 scaled
     assert np.isclose(A[0, 0], 0.5)