add vindex test

Author: TomNicholas

tests/test_indexing.py

@@ -2041,6 +2041,18 @@ async def test_async_oindex(self, store, indexer, expected):
         result = await async_zarr.oindex.getitem(indexer)
         assert_array_equal(result, expected)
 
+    @pytest.mark.parametrize(
+        "indexer,expected", 
+        [
+            (([0], [0]), np.array(1)),
+            (([0, 1], [0, 1]), np.array([1, 4])),
+        ],
+    )
     @pytest.mark.asyncio
-    async def test_async_vindex(self):
-        ...
+    async def test_async_vindex(self, store, indexer, expected):
+        z = zarr.create_array(store=store, shape=(2, 2), chunks=(1, 1), zarr_format=3, dtype="i8")
+        z[...] = np.array([[1, 2], [3, 4]])
+        async_zarr = z._async_array
+
+        result = await async_zarr.vindex.getitem(indexer)
+        assert_array_equal(result, expected)