beta version for folder rename

editors/code/src/client.ts

@@ -51,12 +51,24 @@ export function createClient(serverPath: string, cwd: string, extraEnv: Env): lc
         'Rust Analyzer Language Server Trace',
     );
 
+    const workspace:lc.WorkspaceMiddleware = {
+        willRenameFiles:function<P extends vscode.FileRenameEvent,R extends Thenable<vscode.WorkspaceEdit | null | undefined>>(this: void, data: P, next:(data: P) => R ){
+            // why add this function rather than default:
+            // 1. change `url` parameter to happy format for url crate. (folder should end with '/')
+            // 2. filter some change in here.
+            //     2.1 rename from or to `mod.rs` should be special. 
+            //     2.2 not all folder change should be cared, only those have files with ".rs" postfix.
+            return next(data);
+        }
+    }
+
     const clientOptions: lc.LanguageClientOptions = {
         documentSelector: [{ scheme: 'file', language: 'rust' }],
         initializationOptions: vscode.workspace.getConfiguration("rust-analyzer"),
         diagnosticCollectionName: "rustc",
         traceOutputChannel,
         middleware: {
+            workspace,
             provideDocumentSemanticTokens(document: vscode.TextDocument, token: vscode.CancellationToken, next: DocumentSemanticsTokensSignature): vscode.ProviderResult<vscode.SemanticTokens> {
                 return semanticHighlightingWorkaround(next, document, token);
             },