test and fix indexing for scalar arrays (zarr-developers#2583)

* test and fix indexing for scalar arrays

* fix mypy

Author: brokkoli71

src/zarr/api/asynchronous.py

@@ -579,7 +579,7 @@ async def array(
     z = await create(**kwargs)
 
     # fill with data
-    await z.setitem(slice(None), data)
+    await z.setitem(Ellipsis, data)
 
     return z
 

tests/test_array.py

@@ -881,3 +881,10 @@ async def test_nbytes(
         assert arr._async_array.nbytes == np.prod(arr.shape) * arr.dtype.itemsize
     else:
         assert arr.nbytes == np.prod(arr.shape) * arr.dtype.itemsize
+
+
+async def test_scalar_array() -> None:
+    arr = zarr.array(1.5)
+    assert arr[...] == 1.5
+    assert arr[()] == 1.5
+    assert arr.shape == ()