longitude_slicer is not being covered by any test

[navidcy]

https://app.codecov.io/gh/COSIMA/regional-mom6/blob/main/regional_mom6%2Fregional_mom6.py#L78

Given its complexity we should have at least a simple test to test this.

[ashjbarnes]

Fixed by Navid's longitude slicer test in #112

[navidcy]

You probably meant to say #125

But, truth is that the test doesn't really test anything. Only asserts that longitude_slicer spits out an AssertionError. So I'm reopening this to remind us to add a test that really tests to ensure that longitude_slicer does what it claims it do.

[navidcy]

@ashjbarnes could you give me an example here for a case where the longitude_slicer should take care of the seam?

like... data with lon in [-180, 180] and then ask for

longitude_slicer(data, (150, 200), 'lon')

??

I'm trying to make a test and I'm finding the longitude_slicer to not work as expected. But there is a good chance I am expecting it to work differently from what it does, so a clarification would be helpful.