Test-only dependencies are added to manifest.json

[zombiezen]

I would like dep to treat my test-only dependencies differently than other dependencies. My use case is: I'm publishing a library and that library's tests depend on godebug. I don't want to bloat the vendor directory of projects that import my library, since I don't use it in the implementation, but it seems wrong to list them in my manifest.json. Is this intended behavior? Some docs on manifest.json would go a long way here.

I originally found #306, but that issue appears to be arguing the opposite of what I'd like.

[sdboyer]

Hi, thanks for the issue!

This is definitely not a situation we'd want to have happen - unnecessary vendor bloat in dependees. Happily, though, we're already there. Unlike other comparable systems (npm, cargo, bundler, etc.), having a dependency listed in the manifest does not guarantee its presence in the result (lock or vendor). The real import graph decides what must be present; what's in the manifest just constrains/governs how that'll work. So, having your test-only deps in your manifest will have no impact on your dependees.

And, yeah...we're working on docs: #331 😄