ENH: testing: special case 0D-arrays for check_shape=False (#729)

* Fixing check_shape's else condition

Signed-off-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>

* nit

---------

Signed-off-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>
Co-authored-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>
Co-authored-by: Lucas Colley <lucas.colley8@gmail.com>

Author: prady0t

src/array_api_extra/_lib/_testing.py

@@ -77,10 +77,11 @@ def _check_ns_shape_dtype(
     if check_shape:
         msg = f"shapes do not match: {actual_shape} != f{desired_shape}"
         assert actual_shape == desired_shape, msg
-    else:
+    elif desired.ndim > 0:
         # Ignore shape, but check flattened size. This is normally done by
         # np.testing.assert_array_equal etc even when strict=False, but not for
         # non-materializable arrays.
+        # This check excludes 0d arrays as they are special-cased in NumPy.
         actual_size = math.prod(actual_shape)  # pyright: ignore[reportUnknownArgumentType]
         desired_size = math.prod(desired_shape)  # pyright: ignore[reportUnknownArgumentType]
         msg = f"sizes do not match: {actual_size} != f{desired_size}"