Address PR review feedback (#1466)

- routes.ts: use isAbsolute() before resolve() for proper path validation
- routes.ts: wrap mkdir() in try/catch to map EEXIST/ENOENT/ENOTDIR to 4xx
- DirectoryPicker.tsx: use !browser.currentPath guard to prevent re-fetch loop
- DirectoryPicker.tsx: disable Create button during in-flight requests
- DirectoryPicker.tsx: add fetchEntries to useEffect dependency array
- DirectoryPicker.tsx: client-side validation for folder names
- Add changeset for the new create-folder feature

.changeset/directory-picker-create-folder.md

@@ -0,0 +1,17 @@
+---
+"@runfusion/fusion": minor
+---
+
+Add "New folder" button to DirectoryPicker for project setup
+
+The directory picker in the project setup flow now includes a "New folder"
+button that lets users create folders directly when selecting a project path.
+This includes:
+
+- New `POST /api/create-directory` endpoint for creating directories
+- Create folder UI in DirectoryPicker with inline error handling
+- Keyboard support (Enter to create, Escape to cancel)
+- Client-side validation for folder names (no path separators or traversal)
+
+Also fixes a bug where navigating into an empty folder would revert to the
+previous directory.

packages/dashboard/app/components/DirectoryPicker.tsx

@@ -74,13 +74,12 @@ export function DirectoryPicker({ value, onChange, placeholder, onInputKeyDown,
     });
   }, []);
 
-  // Fetch when browser opens
+  // Fetch when browser opens (only for the initial open before any path has been fetched)
   useEffect(() => {
-    if (browser.isOpen && !browser.loading && browser.entries.length === 0 && !browser.error) {
-      // Use browser.currentPath if available (user has navigated), otherwise fall back to value prop
-      fetchEntries(browser.currentPath || value || undefined, browser.showHidden);
+    if (browser.isOpen && !browser.loading && !browser.currentPath && !browser.error) {
+      fetchEntries(value || undefined, browser.showHidden);
     }
-  }, [browser.isOpen, browser.loading, browser.entries.length, browser.error, value, browser.showHidden, fetchEntries, nodeId, localNodeId]);
+  }, [browser.isOpen, browser.loading, browser.currentPath, browser.error, value, browser.showHidden, fetchEntries, nodeId, localNodeId]);
 
   const handleNavigate = useCallback(
     (path: string) => {
@@ -106,7 +105,8 @@ export function DirectoryPicker({ value, onChange, placeholder, onInputKeyDown,
     if (browser.isOpen && browser.currentPath) {
       fetchEntries(browser.currentPath, browser.showHidden);
     }
-  }, [browser.showHidden]);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [browser.showHidden, fetchEntries]);
 
   const handleToggleCreateFolder = useCallback(() => {
     setBrowser((prev) => ({
@@ -120,12 +120,22 @@ export function DirectoryPicker({ value, onChange, placeholder, onInputKeyDown,
   const handleCreateFolder = useCallback(async () => {
     if (!newFolderName.trim() || !browser.currentPath) return;
 
+    // Validate folder name doesn't contain path separators or traversal
+    const trimmedName = newFolderName.trim();
+    if (trimmedName.includes("/") || trimmedName.includes("\\") || trimmedName.includes("..")) {
+      setBrowser((prev) => ({
+        ...prev,
+        createFolderError: "Folder name cannot contain path separators or '..'",
+      }));
+      return;
+    }
+
     // Normalize path separator for the current platform by using the same
     // separator already present in currentPath
     const sep = browser.currentPath.includes("\\") ? "\\" : "/";
     const folderPath = browser.currentPath.endsWith(sep)
-      ? browser.currentPath + newFolderName.trim()
-      : browser.currentPath + sep + newFolderName.trim();
+      ? browser.currentPath + trimmedName
+      : browser.currentPath + sep + trimmedName;
 
     setBrowser((prev) => ({ ...prev, loading: true, createFolderError: null }));
     try {
@@ -287,7 +297,7 @@ export function DirectoryPicker({ value, onChange, placeholder, onInputKeyDown,
                   type="button"
                   className="btn btn-sm btn-primary"
                   onClick={handleCreateFolder}
-                  disabled={!newFolderName.trim()}
+                  disabled={!newFolderName.trim() || browser.loading}
                 >
                   {t("dirPicker.createFolderConfirm", "Create")}
                 </button>

packages/dashboard/src/routes.ts

@@ -4463,22 +4463,22 @@ export function createApiRoutes(store: TaskStore, options?: ServerOptions): Rout
    */
   router.post("/create-directory", async (req, res) => {
     try {
-      const { resolve } = await import("node:path");
+      const { resolve, isAbsolute } = await import("node:path");
       const { mkdir, stat } = await import("node:fs/promises");
 
-      const rawPath = req.body?.path as string | undefined;
+      const rawPath = typeof req.body?.path === "string" ? req.body.path.trim() : "";
       if (!rawPath) {
         throw badRequest("Path is required");
       }
 
       // Validate: must be absolute, no .. traversal
-      const resolvedPath = resolve(rawPath);
+      if (!isAbsolute(rawPath)) {
+        throw badRequest("Path must be absolute");
+      }
       if (rawPath.includes("..")) {
         throw badRequest("Path must not contain '..' traversal");
       }
-      if (resolvedPath !== resolve(resolvedPath)) {
-        throw badRequest("Path must be absolute");
-      }
+      const resolvedPath = resolve(rawPath);
 
       // Check if path already exists
       try {
@@ -4512,7 +4512,21 @@ export function createApiRoutes(store: TaskStore, options?: ServerOptions): Rout
       }
 
       // Create the directory
-      await mkdir(resolvedPath);
+      try {
+        await mkdir(resolvedPath);
+      } catch (err: unknown) {
+        const e = err as NodeJS.ErrnoException;
+        if (e.code === "EEXIST") {
+          throw badRequest("Directory already exists");
+        }
+        if (e.code === "ENOENT") {
+          throw badRequest("Parent directory does not exist");
+        }
+        if (e.code === "ENOTDIR") {
+          throw badRequest("Parent path is not a directory");
+        }
+        throw err;
+      }
 
       res.json({ success: true, path: resolvedPath });
     } catch (err: unknown) {