".indexes" not updated when setting values through ".values"

[kefirbandi]

MCVE Code Sample

import xarray as xr

da1 = xr.DataArray([1,2],dims=['x'],coords={'x':[0,1]})

print(da1.indexes)
da1['x'].values = [1,2]
print(da1.indexes)
print('--------')
print(da1['x'])

>>> x: Int64Index([0, 1], dtype='int64', name='x')
    x: Int64Index([0, 1], dtype='int64', name='x')
    --------
    <xarray.DataArray 'x' (x: 2)>
    array([1, 2])
    Coordinates:
      * x        (x) int32 1 2

Expected Output

x: Int64Index([0, 1], dtype='int64', name='x')
x: Int64Index([1, 2], dtype='int64', name='x')
--------
<xarray.DataArray 'x' (x: 2)>
array([1, 2])
Coordinates:
  * x        (x) int32 1 2

Problem Description

• .indexes gets out of sync with the values stored in the array
• this is unfortunate as alignment with other array is done through .indexes

The issue does not occur if I
a, either do not call ".indexes" before setting the value, or
b, call da1['x'] = [1,2] instead of da1['x'].values = [1,2]

Output of xr.show_versions()

INSTALLED VERSIONS ------------------ commit: None python: 3.7.3 | packaged by conda-forge | (default, Jul 1 2019, 22:01:29) [MSC v.1900 64 bit (AMD64)] python-bits: 64 OS: Windows OS-release: 10 machine: AMD64 processor: Intel64 Family 6 Model 60 Stepping 3, GenuineIntel byteorder: little LC_ALL: None LANG: None LOCALE: None.None libhdf5: 1.10.5 libnetcdf: 4.6.3 xarray: 0.14.1 pandas: 0.25.1 numpy: 1.17.1 scipy: 1.3.1 netCDF4: 1.5.2 pydap: None h5netcdf: None h5py: 2.10.0 Nio: None zarr: None cftime: 1.0.3.4 nc_time_axis: None PseudoNetCDF: None rasterio: None cfgrib: None iris: None bottleneck: None dask: 2.4.0 distributed: 2.5.1 matplotlib: 3.1.1 cartopy: None seaborn: 0.9.0 numbagg: None setuptools: 41.2.0 pip: 19.2.3 conda: None pytest: 5.1.2 IPython: 7.8.0 sphinx: 2.2.0

[dcherian]

closing in favour of #3470 . Please use da1.assign_coords or da1["x"] = ... instead.