Add API to list versions

[alexarchambault]

Use like

import scala.concurrent.ExecutionContext.Implicits.global
import coursier._
val availableVersions = Versions()
  .withModule(mod"org.scala-lang:scala-library")
  .versions()
  .unsafeRun()
  .available // Seq[String]

[fthomas]

Wow, this looks like it could be used in Scala Steward to find new versions instead of going through sbt and sbt-updates. This has the potential to make Scala Steward a lot faster.

Thanks @alexarchambault!

[alexarchambault]

@fthomas But don't you need to start sbt anyway to know about the dependencies themselves (before checking for possible updates)?

[alexarchambault]

FYI, I have a project in the work, that aims to list dependencies outside of sbt itself, like this. With those files, it should be possible to e.g. have a single JVM checking for updates for as many projects as necessary. (My goal was to ping you about it as a I'll publicly announce it :)

[fthomas]

You're right. Not all invocations of sbt can be eliminated only those that check for updates of all known dependencies.

deps looks cool. Finally a principled way to organize dependencies where it is totally clear where version numbers are defined! It should be easy for Scala Steward to also update deps.json files. Even if a project does not use sbt. This is exciting!

[fthomas]

@alexarchambault I'm now using Coursier exclusively to find new updates (scala-steward-org/scala-steward#1209) and it is working great so far. Going through all repos now takes 30-40 minutes instead of 5-6 hours. It is so fast now that it had been blacklisted by Maven Central a few times and I had to add a rate limiter to slow it down. :-)

Thanks again for this great addition to Coursier!

[alexarchambault]

Thanks for the feedback, @fthomas!

[fthomas]

@alexarchambault I was wondering if Versions does take mirrors into account? My current understanding of the code is that it does not, but I'm not sure.

I'm still having issues with Maven Central so I tried using a mirror but that didn't help for getting versions. WDYT, should support for mirrors be added to Versions?

[fthomas]

I added minimal support for mirrors (by copying code from Resolve) here and it works for me locally: master...fthomas:topic/use-mirrors-in-versions

Should I extend that and also add mirrorConfFiles and mirrors fields to Version so that mirrors can also be set via the API and then open a PR with these changes?

[fthomas]

PR for mirrors support: #1515