Created checking function for xarray.DataArray and throw an error if not

[Badboy-16]

I had a go to fix #14

In the histogram() (xhist()) function, I added some code to check if the object passed to the function is an instance of xarray.DataArray, and if not, throw a TypeError.

[codecov[bot]]

Codecov Report

Merging #54 (5d7bfd7) into master (e95d96a) will increase coverage by 0.05%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #54      +/-   ##
==========================================
+ Coverage   95.74%   95.79%   +0.05%     
==========================================
  Files           3        3              
  Lines         235      238       +3     
  Branches       67       69       +2     
==========================================
+ Hits          225      228       +3     
  Misses          7        7              
  Partials        3        3              

Impacted Files	Coverage Δ
xhistogram/xarray.py	91.52% <100.00%> (+0.45%)	:arrow_up:

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[dougiesquire]

Also, it looks as though your additions are failing the pre-commit test. You can run the tests locally to work out the issues by following the instructions here. Let me know if you have any difficulties.

[Badboy-16]

Thanks @dougiesquire I pushed a new commit regarding the above comments after the pre-commit test is successful locally. Please let me know if there are additional issues :)

[dougiesquire]

Great, pre-commit is passing now 👍. To keep the test coverage high, you could also add a test to xhistogram.tesy.test_xarray.py that checks your input test (sorry, I should have mentioned this sooner). Something like:

def test_input_type_check():
    with pytest.raises(TypeError):
        # Try pass a numpy array to xhistogram

[Badboy-16]

It's ok. I just added a test in the latest commit. 😃

[dougiesquire]

Great - all checks passing now, so I'll merge. Thanks for your contribution @Badboy-16!