Need to add trailing-slash redirect, also.

Always want the browser to recheck this endpoint, in case the
redirect target changes.

Still need to actually test the latest logic.

Switch latest from a redirect to /pypi/{name}/json, and instead
duplicate the version-search logic. This should make `latest` robust
against any future changes to the `json_project` logic.

Implement latest-stable and latest-unstable logic.

Need to fix unstable query (or test?), is redirecting to the
most recent stable version instead of most recent prerelease
for project_with_pre

Apparently, the _pypi_ordering is a function of the order in which
Releases are added to a Project.

Seems potentially brittle.

[skip ci]

2) Draft latest JSON doc chunk

[skip ci]

3) Add docs for 'latest' web UI endpoints

Plus a bit of tweaking to the JSON docs language.

Refreshing base branch underneath the PR.

Not that bad! The sqlalchemy magic is pretty darn intuitive!

Getting errors on local tests; will see how CI does.

Depending on how the various version lookups are called,
project.latest_version may itself return None. So, breaking up
the attribute access chain will be more robust.

Could have used .getattr() here, but stringifying the member names
in the actual codebase (as opposed to in test code) seemed imprudent.

Instead of testing them as redirects, as originally implemented,
they are now tested via catching the call-through to the underlying
json_release() JSON API function.

Refresh branch base.

Fixtures allow monkeypatching; making them class-scope keeps
their definitions closer to the tests and prevents (possibly
undesirably) re-use elsewhere.

If they end up needed elsewhere, they can easily be refactored
out to conftest.py.

As noted in discussion in pypi#8615, zero or multiple query results in this
case are a pathological scenario.

No failures introduced to test suite on the change.

Per pypi#8615 (comment)

JSON API views now directly return, rather than redirecting.

Per
pypi#8615 (review)

In the 'latest' views of views.py, pre-fetch the release
from the project first, then handle appropriately given
the possibility for None.

Addresses the following PR review comments:

-
https://github.com/pypa/warehouse/pull/8615/files/ed0baa180d8bd628e80fcd37450c9d4d60dd5b9d?file-filters%5B%5D=.py#r619663916
-
https://github.com/pypa/warehouse/pull/8615/files/ed0baa180d8bd628e80fcd37450c9d4d60dd5b9d?file-filters%5B%5D=.py#r619663799
-
https://github.com/pypa/warehouse/pull/8615/files/ed0baa180d8bd628e80fcd37450c9d4d60dd5b9d?file-filters%5B%5D=.py#r619663874

For completeness, and to satisfy 100% coverage requirement.

Addresses pypi#8615 (comment).

The database queries inline here may be duplicative; will check
in a subsequent commit.

The 'latest' members off of the Project model now return
fully-realized Release instances, making a subsequent database
call unnecessary.

Latest json pr review

Should be removed before merging pypi#8615

This reverts commit c6f664a.