id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
1615599224,I_kwDOAMm_X85gTBZ4,7597,Interpolate_na: max_map argument not working at array boundaries,42680748,closed,0,,,6,2023-03-08T16:56:36Z,2023-03-16T18:55:58Z,2023-03-16T18:55:58Z,CONTRIBUTOR,,,,"### What happened?

In the case of multidimensional arrays, the `max_gap` argument of `interpolate_na` is currently not working correctly at the array boundaries. This is likely due to a missing ""dim"" argument in the max() aggregation in `xarray.core.missing._get_nan_block_lengths`, I think.

### What did you expect to happen?

In the following code example, due to `max_gap=2`, no extrapolation should be performed for the second row. Currently, this is the case, the output created is:

```
<xarray.DataArray (x: 2, y: 5)>
array([[1., 2., 3., 4., 5.],
       [1., 2., 3., 4., 5.]])
Coordinates:
  * x        (x) int64 0 1
  * y        (y) int64 0 1 2 3 4
```

### Minimal Complete Verifiable Example

```Python
import xarray as xr
import numpy as np
da=xr.DataArray([[1, 2,3,4, np.nan],[1,2, np.nan, np.nan, np.nan]], coords=[('x', [0,1]), ('y', [0,1,2,3,4])])
da_interp=da.interpolate_na(dim='y', max_gap=2, fill_value='extrapolate')
print(da_interp)
```


### MVCE confirmation

- [X] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
- [X] Complete example — the example is self-contained, including all data and the text of any traceback.
- [ ] Verifiable example — the example copy & pastes into an IPython prompt or [Binder notebook](https://mybinder.org/v2/gh/pydata/xarray/main?urlpath=lab/tree/doc/examples/blank_template.ipynb), returning the result.
- [X] New issue — a search of GitHub Issues suggests this is not a duplicate.

### Relevant log output

_No response_

### Anything else we need to know?

I added the missing dim argument and adapted the test cases (Currently, there was no test case for fully multidimensional arrays with a gap at the end).

### Environment

<details>

INSTALLED VERSIONS
------------------
commit: None
python: 3.10.5 | packaged by conda-forge | (main, Jun 14 2022, 07:04:59) [GCC 10.3.0]
python-bits: 64
OS: Linux
OS-release: 5.4.0-135-generic
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8
LOCALE: ('en_US', 'UTF-8')
libhdf5: 1.12.2
libnetcdf: 4.9.0

xarray: 2023.2.0
pandas: 1.5.3
numpy: 1.23.5
scipy: 1.8.1
netCDF4: 1.6.1
pydap: None
h5netcdf: None
h5py: None
Nio: None
zarr: None
cftime: 1.6.2
nc_time_axis: None
PseudoNetCDF: None
rasterio: None
cfgrib: None
iris: None
bottleneck: 1.3.5
dask: 2022.10.2
distributed: None
matplotlib: 3.6.3
cartopy: None
seaborn: None
numbagg: 0.2.1
fsspec: 2022.10.0
cupy: None
pint: 0.20.1
sparse: None
flox: 0.6.8
numpy_groupies: 0.9.20
setuptools: 58.1.0
pip: 23.0.1
conda: None
pytest: None
mypy: None
IPython: 8.6.0
sphinx: None



</details>
","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/7597/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue