mdoc VS ScalaCheck

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

Regarding numbers 2 and 3, I believe you are describing "property-based testing"[0]. A Scala version of this is ScalaCheck and can be found here[1].

There appears to be at least one Rust library which claims to provide same, but I am not a Rust developer so cannot recommend any for fitness of purpose.

0 - https://hypothesis.works/articles/what-is-property-based-tes...

1 - https://github.com/typelevel/scalacheck/blob/main/doc/UserGu...

And the readmes and tutorials written for the major libraries are some of the best, and most concise out there. Seriously, even the old stuff, like scalacheck's guide is really good. Compare that to hypothesis. The hypothesis uses readthedocs, but other than the window dressing, much better. Try to find similar concise guides for major Java projects outside of spring boot. They're all external to the projects, published on Baeldung.

Write your test as properties that must be held, and let the framework generate random values and apply the function to thus values and compare the output by those properties. Take a look to ScalaCheck for that approach.