Ensure client self hrefs don't end in '/'

[gadomski]

Related Issue(s):

• Closes Do something when STAC endpoint url ends with "/" #369

Description:

Our url construction is a bit naïve -- we use basic string formatting, e.g.

pystac-client/pystac_client/client.py

Line 257 in 3f305e2

url = f"{self.get_self_href()}/collections"

As raised in #369, this can lead to request urls containing double //, which breaks some APIs (e.g. out-of-the-box stac-fastapi). This PR does the simplest-possible fix by ensuring that a Client's self href doesn't end in a slash.

PR Checklist:

• Code is formatted
• Tests pass
• Changes are added to the CHANGELOG

[codecov-commenter]

Codecov Report

Base: 85.30% // Head: 85.31% // Increases project coverage by +0.01% 🎉

Coverage data is based on head (80d7363) compared to base (a7fdec1).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #373      +/-   ##
==========================================
+ Coverage   85.30%   85.31%   +0.01%     
==========================================
  Files          11       11              
  Lines         796      797       +1     
==========================================
+ Hits          679      680       +1     
  Misses        117      117              

Impacted Files	Coverage Δ
pystac_client/client.py	85.00% <100.00%> (+0.15%)	⬆️

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[pjhartzell]

LGTM

[m-mohr]

@gadomski I don't think this is a good idea. We recently had a similar case in STAC Browser:

• http://example.com/api doesn't work
• http://example.com/api/ works (and was exposed in self link)
• http://example.com/api//collections didn't work
• http://example.com/api/collections works

Not sure why this API implementation works this way, but removing the slash from the "self URL" was also my first instinct, but quickly I got complaints. So I think the right fix for this can only be to construct the URLs correctly when merging URI parts.

[gadomski]

Hm, it's a good point -- this PR makes the assumption that we know what's best w.r.t. trailing slashes on the root endpoint, but that's not always the case.

I'll cook up a more robust solution in a new PR.