fix: ak.to_parquet for a record-like non-Record (#3175)

* fix: ak.to_parquet for a record-like non-Record

* style: pre-commit fixes

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Ianna Osborne <ianna.osborne@cern.ch>

src/awkward/operations/ak_to_parquet.py

@@ -314,7 +314,7 @@ def get_layout_and_table(x):
     else:
         column_prefix = ()
 
-    if isinstance(data, ak.Record):
+    if isinstance(layout, ak.record.Record):
         form = layout.array.form
     else:
         form = layout.form

tests/test_3174_to_parquet_record.py

@@ -0,0 +1,25 @@
+# BSD 3-Clause License; see https://github.com/scikit-hep/awkward/blob/main/LICENSE
+
+from __future__ import annotations
+
+import os
+
+import pytest
+
+import awkward as ak
+
+pytest.importorskip("pyarrow.parquet")
+
+
+def test(tmp_path):
+    filename = os.path.join(tmp_path, "whatever.parquet")
+
+    px = ak.Array([[1.0, 2.0], [3.0], [], [4.0, 5.0, 6.0]])
+    py = ak.Array([[0.5, 1.5], [2.5], [], [3.5, 4.5, 5.5]])
+    pz = ak.Array([[0.2, 1.2], [2.2], [], [3.2, 4.2, 5.2]])
+    e = ak.Array([[0.1, 1.1], [2.1], [], [3.1, 4.1, 5.1]])
+    data = {"px": px, "py": py, "pz": pz, "e": e}  # not quite a record
+
+    ak.to_parquet(data, filename)
+
+    assert ak.from_parquet(filename).tolist() == ak.to_list(ak.to_layout(data))