Test no-data case too

fsspec/implementations/memory.py

@@ -220,6 +220,8 @@ def cp_file(self, path1, path2, **kwargs):
             raise FileNotFoundError(path1)
 
     def cat_file(self, path, start=None, end=None, **kwargs):
+        if "refs.0.parq" in path:
+            breakpoint()
         logger.debug("cat: %s", path)
         path = self._strip_protocol(path)
         try:

fsspec/implementations/tests/test_reference.py

@@ -802,5 +802,25 @@ def test_parquet_no_data(m):
     )
     lz.flush()
 
-    breakpoint()
     assert (arr[:] == 1).all()
+
+
+def test_parquet_no_references(m):
+    zarr = pytest.importorskip("zarr")
+    lz = fsspec.implementations.reference.LazyReferenceMapper.create(
+        "memory://out.parq", fs=m
+    )
+
+    g = zarr.open_group(lz, mode="w")
+    arr = g.create_dataset(
+        name="one",
+        dtype="int32",
+        shape=(),
+        chunks=(),
+        compression=None,
+        fill_value=1,
+    )
+    lz.flush()
+    arr[...]
+
+    assert arr[...].tolist() == 1  #  scalar, equal to fill value