Normalize hrefs while skipping unresolved links

[gadomski]

Related Issue(s):

• Closes Normalize URLs and set link types for newly added entities #284

Description:

Adds a skip_unresolved argument to Catalog.normalize_hrefs and Catalog.normalize_and_save. Instead of using Catalog.get_items and Catalog.get_children (which resolve their links), we re-implement with additional logic to conditionally skip unresolved links. We considered pushing skip_unresolved all the way down into Link.get_stac_object, but this seemed like overkill, since the motivating use-case for skip_unresolved is to avoid walking the whole tree when normalizing (#284).

Because save already skips unresolved links, this enables normalize_and_save to only touch objects that have been added to the tree or modified (and therefore resolved).

Note this isn't exactly the solution proposed by @matthewhanson in #284, since the hrefs newly-added entities aren't normalized. These changes are only confined to normalize.

This is a feature-adding, backwards compatible change that could be incorporated in a MINOR release.

cc @l0b0

PR Checklist:

• Code is formatted (run pre-commit run --all-files)
• Tests pass (run scripts/test)
• Documentation has been updated to reflect changes, if applicable
• This PR maintains or improves overall codebase code coverage.
• Changes are added to the CHANGELOG. See the docs for information about adding to the changelog.

[codecov-commenter]

Codecov Report

Base: 90.09% // Head: 90.12% // Increases project coverage by +0.02% 🎉

Coverage data is based on head (4c149a8) compared to base (b0aec93).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #900      +/-   ##
==========================================
+ Coverage   90.09%   90.12%   +0.02%     
==========================================
  Files          47       47              
  Lines        6057     6064       +7     
  Branches      905      909       +4     
==========================================
+ Hits         5457     5465       +8     
  Misses        420      420              
+ Partials      180      179       -1     

Impacted Files	Coverage Δ
pystac/catalog.py	91.96% <100.00%> (+0.37%)	⬆️

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[matthewhanson]

This looks fine to me, I think it's a good change - in most cases of adding new items to a catalog you shouldn't need to resolve anything that isn't newly added (i.e., resolved).

But I'm not sure I follow this:

Note this isn't exactly the solution proposed by @matthewhanson in https://github.com/stac-utils/pystac/issues/284, since the hrefs newly-added entities aren't normalized. These changes are only confined to normalize.

What do you mean by newly-added entities aren't normalized?

[gadomski]

What do you mean by newly-added entities aren't normalized?

If I understood #284 correctly, you were proposing a change where

collection.add_item(item)

would auto-magically normalize the item href (without having to call collection.normalize_hrefs()). This PR does not do that.