fix static file serving in local dev, fix edge case in prod

[syphar]

fixes a production edge case that would have lead to wrong cache headers when someone locally deletes files from the static or vendor directories that were there at built-time.

Also we're fixing a bug when you were locally running the docs.rs webserver from the repository-root. In this case the static assets weren't found, because they don't live in the repo root any more. We fallback to CARGO_MANIFEST_DIR now.

I added a unit-test for the wrong cache headers in this edge-case, and a first "real" integration test at the repo root that just so happens to test the static asset fetching in development. More integration tests will be added.

[GuillaumeGomez]

Write a unit test which starts the server from top level and query a static resource?

[syphar]

Write a unit test which starts the server from top level and query a static resource?

now after having slept, I can see it.

starting a test from the top level would either mean re-introducing the top-level crate,

but perhaps I can change the CWD for a single test-case

[GuillaumeGomez]

Yep, changing the cwd was what I had in mind.

[syphar]

Yep, changing the cwd was what I had in mind.

but cwd is always per-process, so with parallel test execution you might break stuff, or we have to set threads=1.

But I have another, cleaner idea.

I'll inject the root dir into the router builder, and write a test on a "broken" router.

[GuillaumeGomez]

No I mean, when you use Command, you can give it a cwd. That's what I had in mind.

[syphar]

@GuillaumeGomez added some tests, I think this is the better approach.

[GuillaumeGomez]

Does that mean it works wherever we start the server?

[syphar]

Does that mean it works wherever we start the server?

in a dev project, yes.

in the built binary, or docker container, no.

the fallback is CARGO_MANIFEST_DIR, which is the path on the developer machine making the build.

So it might work whereever you try in this repo :

[GuillaumeGomez]

Awesome! Then please update docs as well then I'll approve. :)

[syphar]

@GuillaumeGomez like this?

[GuillaumeGomez]

Yes exactly, thanks!