fix mypy for ScalarWrapper

Author: brokkoli71

src/zarr/core/buffer/core.py

@@ -154,16 +154,13 @@ def view(self, dtype: npt.DTypeLike) -> Self:
     def astype(
         self, dtype: npt.DTypeLike, order: Literal["K", "A", "C", "F"] = "K", *, copy: bool = True
     ) -> Self:
-        if copy:
-            return ScalarWrapper(dtype.type(self._value))
-        self._value = dtype.type(self._value)
-        return self
+        raise TypeError("ScalarWrapper object has no astype()")
 
     def fill(self, value: Any) -> None:
         self._value = value
 
     def copy(self) -> Self:
-        return ScalarWrapper(self._value)
+        return self.__class__(self._value)
 
     def transpose(self, axes: SupportsIndex | Sequence[SupportsIndex] | None = None) -> Self:
         return self
@@ -175,7 +172,7 @@ def all(self) -> bool:
         return bool(self._value)
 
     def __eq__(self, other: object) -> Self:
-        return ScalarWrapper(self._value == other)
+        return self.__class__(self._value == other)
 
     def __repr__(self) -> str:
         return f"ScalarWrapper({self._value!r})"
@@ -208,7 +205,7 @@ def __neg__(self) -> Any:
         return -self._value
 
     def __abs__(self) -> Any:
-        if isinstance(self._value, (int, float, complex)):
+        if hasattr(self._value, "__abs__"):
             return abs(self._value)
         raise TypeError(f"bad operand type for abs(): '{self._value.__class__.__name__}'")
 

tests/test_buffer.py

@@ -62,10 +62,8 @@ async def test_async_array_prototype() -> None:
         prototype=my_prototype,
     )
     got = await a.getitem(selection=(slice(0, 9), slice(0, 9)), prototype=my_prototype)
-    # ignoring a mypy error here that TestNDArrayLike doesn't meet the NDArrayLike protocol
-    # The test passes, so it clearly does.
-    assert isinstance(got, TestNDArrayLike)  # type: ignore[unreachable]
-    assert np.array_equal(expect, got)  # type: ignore[unreachable]
+    assert isinstance(got, TestNDArrayLike)
+    assert np.array_equal(expect, got)
 
 
 @gpu_test
@@ -115,10 +113,8 @@ async def test_codecs_use_of_prototype() -> None:
         prototype=my_prototype,
     )
     got = await a.getitem(selection=(slice(0, 10), slice(0, 10)), prototype=my_prototype)
-    # ignoring a mypy error here that TestNDArrayLike doesn't meet the NDArrayLike protocol
-    # The test passes, so it clearly does.
-    assert isinstance(got, TestNDArrayLike)  # type: ignore[unreachable]
-    assert np.array_equal(expect, got)  # type: ignore[unreachable]
+    assert isinstance(got, TestNDArrayLike)
+    assert np.array_equal(expect, got)
 
 
 @gpu_test