Add indexing tests

Author: dcherian

tests/test_properties.py

@@ -1,5 +1,5 @@
-import numpy as np
 import pytest
+from numpy.testing import assert_array_equal
 
 import zarr
 from zarr import Array
@@ -11,7 +11,6 @@
 import hypothesis.strategies as st  # noqa
 from hypothesis import given, settings  # noqa
 
-
 #### TODO: Provide this in zarr.strategies
 # Copied from Xarray
 _attr_keys = st.text(st.characters(), min_size=1)
@@ -119,4 +118,25 @@ def arrays(draw, *, stores=stores, arrays=np_arrays, paths=paths, array_names=ar
 def test_roundtrip(data):
     nparray = data.draw(np_arrays)
     zarray = data.draw(arrays(arrays=st.just(nparray)))
-    np.testing.assert_equal(nparray, zarray[:])
+    assert_array_equal(nparray, zarray[:])
+
+
+# @pytest.mark.slow
+@given(data=st.data())
+def test_basic_indexing(data):
+    def is_negative_slice(idx):
+        return isinstance(idx, slice) and idx.step is not None and idx.step < 0
+
+    zarray = data.draw(arrays())
+    nparray = zarray[:]
+    indexer = data.draw(
+        npst.basic_indices(shape=nparray.shape).filter(
+            lambda idxr: (
+                not (
+                    is_negative_slice(idxr)
+                    or (isinstance(idxr, tuple) and any(is_negative_slice(idx) for idx in idxr))
+                )
+            )
+        )
+    )
+    assert_array_equal(nparray[indexer], zarray[indexer])