Make "Go to latest version" point to /latest/

[jsha]

Still trying to get tests to pass, but figured I'd post up what I've got so far.

[jyn514]

Looks great, thanks!

[jsha]

Sorry, forgot to comment along with the push. I updated along the lines we discussed, but I'm still struggling with getting some of the tests to pass. I think I don't fully understand what they're doing yet. If you have a chance to take a look I'd appreciate, otherwise I can probably puzzle through it next weekend.

[jyn514]

@jsha hmm, so this seems like a larger problem - target-redirect doesn't support latest, only specific version numbers. I think it's ok to change the tests to expect latest as long as we make sure that page doesn't 404.

[jsha]

target-redirect does appear to support latest:

$ curl -i https://docs.rs/crate/rustls/latest/target-redirect/x86_64-unknown-linux-gnu/rustls/index.html
HTTP/2 302 
content-length: 0
location: https://docs.rs/rustls/latest/rustls/index.html

[jyn514]

Ok great, I think you can just update the tests to match the new behavior then :)

[jsha]

Alright, I've got almost all of them updated, except this one, which now gets a 404:

thread 'web::rustdoc::test::redirect_latest_with_all_yanked::_true' panicked at 'failed to GET /crate/dummy/latest/target-redirect/x86_64-unknown-linux-gnu/dummy/index.html: 404 Not Found', src/test/mod.rs:47:5

I don't really understand - what's the expected behavior when all versions are yanked? Do I need to add code such that target-redirect will go to a yanked version if there's no unyanked version available?

[Nemo157]

Previously, the behaviour when all versions were yanked is that you could not load the crate using any of the semver/wildcard requests, only an exact version number would load; and if you were on an old version of the crate then it would show a link to the latest version still.

I'm not sure what the behaviour should be after this change, changing the latest version link on those pages to /latest/ would presumably not work since that's not an exact version link; but not changing it would be an annoying inconsistency. One option would be to just drop the latest version redirect in those cases, a fully yanked crate is a real edge case and you probably don't want to be updating it to the latest version (especially since you would have to manually build your Cargo.lock to do the update).

[jsha]

By "drop the latest version redirect in those cases," you mean don't generate the link in the header?

[Nemo157]

Exactly.

[jsha]

Alright, I checked and that's actually the current behavior - no link is generated when all versions are yanked. So I pulled out the failing redirect_latest_with_all_yanked test because it was testing a behavior that doesn't happen. Should be ready to go!