issue_comments

Thanks @OriolAbril . I see this is your first PR. Thanks!

Thanks @OriolAbril . This looks good to me. Can you add a note under enhancements in whats-new.rst?

Modified test sounds good to me. I'll open another issue.

Nice job @OriolAbril! you seem to have found a bug where renaming doesn't create an IndexVariable when necessary. I will look into this.

``` ___ TestDataArray.testreset_index_keep_attrs _____

self = <xarray.tests.test_dataarray.TestDataArray object at 0x7f266d36c4d0>

def test_reset_index_keep_attrs(self):
    coord_1 = xr.DataArray([1, 2], dims=["coord_1"], attrs={"attrs": True})
    da = xr.DataArray([1, 0], [coord_1])
    obj = da.reset_index("coord_1").rename({"coord_1_": "coord_1"})

  assert_identical(da, obj)

xarray/tests/test_dataarray.py:1837:

xarray/testing.py:267: in _assert_internal_invariants _assert_dataarray_invariants(xarray_obj)

da = <xarray.DataArray (coord_1: 2)> array([1, 0]) Coordinates: * coord_1 (coord_1) int64 1 2

def _assert_dataarray_invariants(da: DataArray):
    assert isinstance(da._variable, Variable), da._variable
    _assert_variable_invariants(da._variable)

    assert isinstance(da._coords, dict), da._coords
    assert all(isinstance(v, Variable) for v in da._coords.values()), da._coords
    assert all(set(v.dims) <= set(da.dims) for v in da._coords.values()), (
        da.dims,
        {k: v.dims for k, v in da._coords.items()},
    )
    assert all(
        isinstance(v, IndexVariable) for (k, v) in da._coords.items() if v.dims == (k,)

  ), {k: type(v) for k, v in da._coords.items()}

E AssertionError: {'coord_1': <class 'xarray.core.variable.Variable'>}

```