How to test sbt resolvers

Question

On my local machine I have an ivy cache that has been filled by working on multiple projects.

A library X is loaded using resolver Y in project A. This same library X is used in project B, no problems resolving this library because it's in my local cache.

When one of my colleagues loads project B he get's the error that library X could not be resolved. The problem: resolver Y is missing.

How can I test if my sbt project has a complete set of resolvers to resolve all dependencies without removing my ivy cache?

Answer 1

Another even more elegant solution would be to investigate the SBT sources if it is easily possible to setup this behavior as a separate task. The necessary steps could be the same as in my other answer.

1. Extract parameter sbt.ivy.home from update task and provide a parameterized overload for it (if this is possible)
2. Define new task testDependencies see documentation
3. Create tempDirectory
4. Call update(tempDirectory)
5. Gather results
6. Remove tempDirectory
7. Promote results
8. Provide a pull request ;) or an sbt plugin

Answer 2

This command allows you to find if you are missing any updates for the current project. Note that this will not discover any missing resolvers for your plugins.

commands += Command.command("testUpdate") { state =>
  val base = baseDirectory.value
  val newState = Project
    .extract(state)
    .append(Seq(ivyPaths := new IvyPaths(base, Some(base / "tmp-cache"))), state)
  val (s, _) = Project
    .extract(newState)
    .runTask(update, newState)
  s
}

It could be expanded by removing the directory afterwards.