missinglink VS mdoc

You can also use the upstream https://github.com/spotify/missinglink if you're using Maven instead of sbt.

There's been a recent release of missing-link with support for Mult-Release JARs and running analysis on multiple projects concurrently. More info here (applies not only to Scala/sbt, so it's worth linking it here): https://old.reddit.com/r/scala/comments/lxmi4w/sbtmissinglink_032_has_been_released_multirelease/

There are still some issues with MissingLink, like that it can't handle Multi-Release JARs (but that's being fixed I write) or that it uses thread-unsafe caches and so it can't be executed in parallel (and so it can take a long time to finish on big projects with many modules). But taken all together I swear by it. It has already saved us from runtime failures after deployment many times (it's easy to get incompatible versions when working on big projects with big number of dependencies). Instead, we get a red build in CI -- just anybody should expect for goodness sake when using a strongly-typed language like Scala.

Literally what scaladoc is, it comes with sbt. Although, it's better when enhanced with mdoc so that you get the standard microsite template like these. It would be nice to have an sbt serveDocs and if everyone would host their docs for external linking, but javadoc doesn't do that either.

The good news is that scaladoc is produced by default by sbt and published by default. So you can often pull it from the same repository your library jar came from, extract it with zip, and read the docs. But that's also totally unnecessary - javadoc.io allows you to put in your module info and serves the docs for you, so if there's an older version you can access the documentation this way. Rely on the type signatures, since they can't lie, whilst comments (including scaladoc comments) can. Honestly, library authors should be using mdoc and including examples on every public method, and that type of documentation is something you can almost always contribute to a project for a quick pr kudos.

I know it's not new but the "Snippet validation and results (mdoc)" features in mdoc are so cool. Really takes some of the tedium out of working with documentation since you can know that as you evolve your code the compiler will make sure you keep the docs in sync. Whole new level of Readme-Driven Development