sbt server does collectAnalyses on initialize

[olafurpg]

Followup from #4110

steps

Connect to sbt server in a freshly cloned repo like https://github.com/non/spire

problem

sbt server runs collectAnalyses during the initialize handshake, triggering compilation in all projects + platforms locking my sbt shell for a few minutes.

expectation

I expect sbt server not to trigger collectAnalyses during the initialize handshake. A client can trigger collectAnalyses via sbt/exec after initialize, if the client is interested in that action.

Judging from the discussions in #4110, it seems the motivation for running collectAnalyses is to support textDocument/definition. However, only a few sbt server clients use that functionality. Additionally, since collectAnalyses may take a long time in large projects (in scalameta/scalameta I suspect it'll be >10 minutes since we cross-build ~17 modules), the client may want to refine the scope with something like core/collectAnalyses in order to provide a snappier UX.

notes

There is no workaround for clients, this step is hardcoded in sbt server

sbt/main/src/main/scala/sbt/internal/server/LanguageServerProtocol.scala

Line 61 in 187c50c

appendExec(Exec(s"collectAnalyses", Some(r.id), Some(CommandSource(name))))

We want to use sbt server to perform automatic installation in metals (https://github.com/scalameta/metals), but this sbt server behavior is extra unfortunate in our case since the metals client runs a semanticdbEnable command right after initialize, which enables a compiler plugin causing the project to re-compile throwing out the zinc cache from collectAnalyses.

sbt version: 1.1.1

[eed3si9n]

+1 from me. My initial demo usage for sbt server was to make it a lightweight VS Code backend, and at some point it got hardcoded into initialization. But I agree it would be good to get it out of the initial handshake. Maybe fold it into compile?

[olafurpg]

I don't know the details of what collectAnalyses does. From my perspective, sbt server provides a generic solution for clients to trigger tasks and commands via sbt/exec. I would leave it to clients to decide what to do.

[dwijnand]

Maybe fold it into compile?

Only if it's negligible cost to all other non-LSP, direct and indirect users of compile.