3 files changed, 34 insertions, 4 deletions

diff --git a/crates/rust-analyzer/src/caps.rs b/crates/rust-analyzer/src/caps.rs
index 5167a005f..406a93b10 100644
--- a/crates/rust-analyzer/src/caps.rs
+++ b/crates/rust-analyzer/src/caps.rs
@@ -85,8 +85,9 @@ pub fn server_capabilities(client_caps: &ClientCapabilities) -> ServerCapabiliti
                                 matches: Some(FileOperationPatternKind::File),
                                 options: None,
                             },
+                        },
                         FileOperationFilter {
-                            scheme: Some(String::from("untitled")),
+                            scheme: Some(String::from("file")),
                             pattern: FileOperationPattern {
                                 glob: String::from("**"),
                                 matches: Some(FileOperationPatternKind::Folder),
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index c13cdc4e3..176774a77 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -432,9 +432,26 @@ pub(crate) fn handle_will_rename_files(
             // Limit to single-level moves for now.
             match (from_path.parent(), to_path.parent()) {
                 (Some(p1), Some(p2)) if p1 == p2 => {
-                    let new_name = to_path.file_stem()?;
-                    let new_name = new_name.to_str()?;
-                    Some((snap.url_to_file_id(&from).ok()?, new_name.to_string()))
+                    if from_path.is_dir() {
+                        // This is a quick implement, try to use will_rename_file code.
+                        // imitate change the older_folder/mod.rs to older_folder/new_folder.rs
+                        let imitate_from_path = from_path.join("mod.rs");
+                        let new_from_url = imitate_from_path.to_str()?;
+                        let new_from_url = Url::parse(new_from_url).ok()?;
+
+                        let new_folder_name = to_path.file_name()?.to_str()?;
+                        let mut imite_new_file_name  = new_folder_name.to_string();
+                        imite_new_file_name.push_str(".rs");
+                        let new_to = from_path.join(imite_new_file_name);
+                        let new_to = new_to.to_str()?;
+
+                        Some((snap.url_to_file_id(&new_from_url).ok()?, new_to.to_string()))
+                    }
+                    else{
+                        let new_name = to_path.file_stem()?;
+                        let new_name = new_name.to_str()?;
+                        Some((snap.url_to_file_id(&from).ok()?, new_name.to_string()))
+                    }
                 }
                 _ => None,
             }
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index 539e487ec..2a8f2deb4 100644
--- a/editors/code/src/client.ts
+++ b/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);
             },