Revert "Remove --preview as a required argument for ruff server (#…

…12053)"

This reverts commit b28dc9a.

crates/ruff/src/commands/server.rs

@@ -4,7 +4,12 @@ use crate::ExitStatus;
 use anyhow::Result;
 use ruff_server::Server;
 
-pub(crate) fn run_server(_preview: bool, worker_threads: NonZeroUsize) -> Result<ExitStatus> {
+pub(crate) fn run_server(preview: bool, worker_threads: NonZeroUsize) -> Result<ExitStatus> {
+ if !preview {
+ tracing::error!("--preview needs to be provided as a command line argument while the server is still unstable.\nFor example: `ruff server --preview`");
+ return Ok(ExitStatus::Error);
+ }
+
  let server = Server::new(worker_threads)?;
 
  server.run().map(|()| ExitStatus::Success)