Use fire and forget client request to avoid deadlocks (#4150)

Author: gabritto

internal/lsp/progress.go

@@ -44,7 +44,7 @@ func (r *serverProgressReporter) localize(msg *diagnostics.Message, args ...any)
 }
 
 func (r *serverProgressReporter) createWorkDoneProgress(token string) {
-	_, _ = sendClientRequest(r.server.backgroundCtx, r.server, lsproto.WindowWorkDoneProgressCreateInfo, &lsproto.WorkDoneProgressCreateParams{
+	_ = sendClientRequestFireAndForget(r.server, lsproto.WindowWorkDoneProgressCreateInfo, &lsproto.WorkDoneProgressCreateParams{
 		Token: lsproto.IntegerOrString{String: &token},
 	})
 }

internal/lsp/server.go

@@ -305,7 +305,7 @@ func (s *Server) RefreshInlayHints(ctx context.Context) error {
 		return nil
 	}
 
-	if _, err := sendClientRequest(ctx, s, lsproto.WorkspaceInlayHintRefreshInfo, lsproto.NoParams{}); err != nil {
+	if err := sendClientRequestFireAndForget(s, lsproto.WorkspaceInlayHintRefreshInfo, lsproto.NoParams{}); err != nil {
 		return fmt.Errorf("failed to refresh inlay hints: %w", err)
 	}
 	return nil
@@ -316,7 +316,7 @@ func (s *Server) RefreshCodeLens(ctx context.Context) error {
 		return nil
 	}
 
-	if _, err := sendClientRequest(ctx, s, lsproto.WorkspaceCodeLensRefreshInfo, lsproto.NoParams{}); err != nil {
+	if err := sendClientRequestFireAndForget(s, lsproto.WorkspaceCodeLensRefreshInfo, lsproto.NoParams{}); err != nil {
 		return fmt.Errorf("failed to refresh code lens: %w", err)
 	}
 	return nil
@@ -565,6 +565,8 @@ func (s *Server) writeLoop(ctx context.Context) error {
 	}
 }
 
+// WARNING: this should only be called in the async portion of a request handler,
+// otherwise a deadlock can occur.
 func sendClientRequest[Req, Resp any](ctx context.Context, s *Server, info lsproto.RequestInfo[Req, Resp], params Req) (Resp, error) {
 	id := jsonrpc.NewIDString(fmt.Sprintf("ts%d", s.clientSeq.Add(1)))
 	req := info.NewRequestMessage(id, params)