Run task without cache vs cleaning

We want to support a way for clients to run tasks, especially compiles, without cache, i.e. a non-incremental build.

One way to do this is to support a clean request that asks to remove any products of a build target.

Another way would be to add a flag to the compile request, and potentially other tasks, that requests a full rebuild.

What considerations affect the choice of these options, and are there other options?

[olafurpg]

When I think of it more I agree that adding a clean request makes sense. A lot of build tools do support clean and I see value in having a tool-agnostic endpoint for this functionality. The build tool can declare that it doesn’t support clean during the initialize handshake.

[olafurpg]

To fix this ticket I propose to add a new request endpoint buildTarget/clean

// buildTarget/clean: request from client to server
trait CleanParams {
  def targets: List[BuildTargetIdentifier]
}
trait CleanResult {
  
}

Any suggestion what to put in CleanResult? We could add def cleaned: Boolean, where cleaned=true means the clean succeeded and cleaned=false means nothing was cleaned. This would be consistent with LSP workspace/applyEdit https://microsoft.github.io/language-server-protocol/specification#workspace_applyEdit