Fix: Missing axis_wrap_if_negative Record method in both v1 and v2

include/awkward/array/Record.h

@@ -181,6 +181,9 @@ namespace awkward {
     const ContentPtr
       shallow_simplify() const override;
 
+    const int64_t
+      axis_wrap_if_negative(int64_t axis) const;
+
     const ContentPtr
       num(int64_t axis, int64_t depth) const override;
 

src/awkward/_v2/record.py

@@ -102,6 +102,13 @@ def branch_depth(self):
         branch, depth = self._array.branch_depth
         return branch, depth - 1
 
+    def axis_wrap_if_negative(self, axis):
+        if axis == 0:
+            raise ak._v2._util.error(
+                np.AxisError("Record type at axis=0 is a scalar, not an array")
+            )
+        return self._array.axis_wrap_if_negative(axis)
+
     def __getitem__(self, where):
         with ak._v2._util.SlicingErrorContext(self, where):
             return self._getitem(where)

src/libawkward/array/Record.cpp

@@ -308,6 +308,15 @@ namespace awkward {
     return shallow_copy();
   }
 
+  const int64_t
+  Record::axis_wrap_if_negative(int64_t axis) const {
+    if (axis == 0) {
+      throw std::invalid_argument(
+        std::string("Record at axis=0 is a scalar, not an array") + FILENAME(__LINE__));
+    }
+    return array_.get()->axis_wrap_if_negative(axis);
+  }
+
   const ContentPtr
   Record::num(int64_t axis, int64_t depth) const {
     int64_t posaxis = axis_wrap_if_negative(axis);

src/python/content.cpp

@@ -3110,6 +3110,9 @@ make_Record(const py::handle& m, const std::string& name) {
      .def("simplify", [](const ak::Record& self) {
        return box(self.shallow_simplify());
      })
+     .def("axis_wrap_if_negative",
+               &ak::Record::axis_wrap_if_negative,
+               py::arg("axis"))
      .def("copy_to",
           [](const ak::Record& self, const std::string& ptr_lib) -> py::object {
           if (ptr_lib == "cpu") {

tests/v2/test_1565-axis_wrap_if_negative_record.py

@@ -0,0 +1,68 @@
+# BSD 3-Clause License; see https://github.com/scikit-hep/awkward-1.0/blob/main/LICENSE
+
+import pytest  # noqa: F401
+import awkward as ak  # noqa: F401
+import numpy as np  # noqa: F401
+
+to_list = ak._v2.operations.to_list
+
+
+def test_axis_wrap_if_negative_record_v2():
+    dict_cell_chain_field = {
+        "cell1": [
+            {
+                "locus": "TRA",
+                "v_call": "TRAV1",
+                "cdr3_length": 15,
+            },  # <-- represents one chain
+            {"locus": "TRB", "v_call": "TRBV1", "cdr3_length": 12},
+        ],
+        "cell2": [{"locus": "TRA", "v_call": "TRAV1", "cdr3_length": 13}],
+        "cell3": [],
+    }
+
+    r = ak._v2.Record(dict_cell_chain_field)
+
+    with pytest.raises(np.AxisError):
+        r = ak._v2.operations.to_regular(r, 0)
+    r = ak._v2.operations.to_regular(r, 2)
+
+    list_cell_chain_field = [
+        [["TRA", "TRAV1", 15], ["TRB", "TRBV1", 12]],
+        [["TRA", "TRAV1", 13]],
+        [],
+    ]
+
+    a = ak._v2.Array(list_cell_chain_field)
+    a = ak._v2.operations.to_regular(a, 0)
+    a = ak._v2.operations.to_regular(a, 2)
+
+
+def test_axis_wrap_if_negative_record_v1():
+    dict_cell_chain_field = {
+        "cell1": [
+            {
+                "locus": "TRA",
+                "v_call": "TRAV1",
+                "cdr3_length": 15,
+            },  # <-- represents one chain
+            {"locus": "TRB", "v_call": "TRBV1", "cdr3_length": 12},
+        ],
+        "cell2": [{"locus": "TRA", "v_call": "TRAV1", "cdr3_length": 13}],
+        "cell3": [],
+    }
+
+    r = ak.Record(dict_cell_chain_field)
+
+    r = ak.to_regular(r, 0)
+    r = ak.to_regular(r, 2)
+
+    list_cell_chain_field = [
+        [["TRA", "TRAV1", 15], ["TRB", "TRBV1", 12]],
+        [["TRA", "TRAV1", 13]],
+        [],
+    ]
+
+    a = ak.Array(list_cell_chain_field)
+    a = ak.to_regular(a, 0)
+    a = ak.to_regular(a, 2)