Refactor filesystem path resolution and enhance directory browsing logic

src/main/frontend/app/components/directory-picker/directory-picker.tsx

@@ -21,6 +21,7 @@ export default function DirectoryPicker({
   initialPath,
 }: Readonly<DirectoryPickerProperties>) {
   const [currentPath, setCurrentPath] = useState('')
+  const [parentPath, setParentPath] = useState('')
   const [entries, setEntries] = useState<FilesystemEntry[]>([])
   const [selectedEntry, setSelectedEntry] = useState<string | null>(null)
   const [loading, setLoading] = useState(false)
@@ -32,11 +33,11 @@ export default function DirectoryPicker({
     setSelectedEntry(null)
     try {
       const result = await filesystemService.browse(path)
-      setEntries(result)
-      setCurrentPath(path)
+      setEntries(result.entries)
+      setCurrentPath(result.resolvedPath)
+      setParentPath(result.parentPath)
     } catch (error_) {
-      const status = error_ instanceof ApiError ? error_.status : 0
-      if (status === 403) {
+      if (error_ instanceof ApiError && error_.status === 403) {
         setError('Access denied')
       } else {
         setError(error_ instanceof Error ? error_.message : 'Failed to load directories')
@@ -46,6 +47,10 @@ export default function DirectoryPicker({
     }
   }, [])
 
+  const handleNavigateUp = () => {
+    loadEntries(parentPath)
+  }
+
   useEffect(() => {
     if (isOpen) {
       setSelectedEntry(null)
@@ -55,23 +60,7 @@ export default function DirectoryPicker({
 
   if (!isOpen) return null
 
-  const isRoot = !currentPath
-  const canGoUp = !isRoot
-
-  const handleNavigateUp = () => {
-    if (/^[a-zA-Z]:[/\\]?$/.test(currentPath) || currentPath === '/') {
-      loadEntries('')
-      return
-    }
-    const parentPath = currentPath.replace(/[\\/][^\\/]*$/, '')
-    if (!parentPath || parentPath === currentPath) {
-      loadEntries('')
-    } else if (/^[a-zA-Z]:$/.test(parentPath)) {
-      loadEntries(`${parentPath}\\`)
-    } else {
-      loadEntries(parentPath)
-    }
-  }
+  const canGoUp = parentPath !== ''
 
   const handleClick = (entry: FilesystemEntry) => {
     setSelectedEntry(entry.path)

src/main/frontend/app/routes/projectlanding/clone-project-modal.tsx

@@ -24,18 +24,15 @@ export default function CloneProjectModal({
   const [showPicker, setShowPicker] = useState(false)
 
   useEffect(() => {
-    if (isOpen && isLocal) {
-      if (initialPath) {
-        setLocation(initialPath)
-      } else {
-        filesystemService
-          .getDefaultPath()
-          .then(setLocation)
-          .catch(() => setLocation(''))
-      }
-    } else if (isOpen) {
-      setLocation(initialPath ?? '')
+    if (!isOpen || !isLocal) {
+      if (isOpen) setLocation(initialPath ?? '')
+      return
     }
+
+    filesystemService
+      .resolveNearestAccessiblePath(initialPath ?? '')
+      .then(setLocation)
+      .catch(() => setLocation(''))
   }, [isOpen, isLocal, initialPath])
 
   if (!isOpen) return null

src/main/frontend/app/routes/projectlanding/new-project-modal.tsx

@@ -23,18 +23,15 @@ export default function NewProjectModal({
   const [showPicker, setShowPicker] = useState(false)
 
   useEffect(() => {
-    if (isOpen && isLocal) {
-      if (initialPath) {
-        setLocation(initialPath)
-      } else {
-        filesystemService
-          .getDefaultPath()
-          .then(setLocation)
-          .catch(() => setLocation(''))
-      }
-    } else if (isOpen) {
-      setLocation(initialPath ?? '')
+    if (!isOpen || !isLocal) {
+      if (isOpen) setLocation(initialPath ?? '')
+      return
     }
+
+    filesystemService
+      .resolveNearestAccessiblePath(initialPath ?? '')
+      .then(setLocation)
+      .catch(() => setLocation(''))
   }, [isOpen, isLocal, initialPath])
 
   if (!isOpen) return null

src/main/frontend/app/services/filesystem-service.ts

@@ -1,13 +1,13 @@
 import { apiFetch } from '~/utils/api'
-import type { FilesystemEntry } from '~/types/filesystem.types'
+import type { BrowseResult } from '~/types/filesystem.types'
 
 export const filesystemService = {
-  async browse(path = ''): Promise<FilesystemEntry[]> {
+  async browse(path = ''): Promise<BrowseResult> {
     return apiFetch(`/filesystem/browse?path=${encodeURIComponent(path)}`)
   },
 
-  async getDefaultPath(): Promise<string> {
-    const result = await apiFetch<{ path: string }>('/filesystem/default-path')
-    return result.path
+  async resolveNearestAccessiblePath(path: string): Promise<string> {
+    const result = await this.browse(path)
+    return result.resolvedPath
   },
 }

src/main/frontend/app/types/filesystem.types.ts

@@ -1,5 +1,11 @@
 export type EntryType = 'DIRECTORY' | 'FILE'
 
+export interface BrowseResult {
+  resolvedPath: string
+  parentPath: string
+  entries: FilesystemEntry[]
+}
+
 export interface FilesystemEntry {
   name: string
   path: string

src/main/java/org/frankframework/flow/filesystem/BrowseResult.java

@@ -0,0 +1,5 @@
+package org.frankframework.flow.filesystem;
+
+import java.util.List;
+
+public record BrowseResult(String resolvedPath, String parentPath, List<FilesystemEntry> entries) {}

src/main/java/org/frankframework/flow/filesystem/FileSystemStorage.java

@@ -1,6 +1,7 @@
 package org.frankframework.flow.filesystem;
 
 import java.io.IOException;
+import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.util.List;
 
@@ -17,6 +18,17 @@
 	 */
 	List<FilesystemEntry> listDirectory(String path) throws IOException;
 
+	/**
+	 * Returns entries for the given path. If the path does not exist, walks up to
+	 * the nearest accessible ancestor. Falls back to roots if none found.
+	 */
+	default BrowseResult browse(String path) throws IOException {
+		if (path == null || path.isBlank()) {
+			return new BrowseResult("", "", listRoots());
+		}
+		return browseNearestAccessible(path);
+	}
+
 	String readFile(String path) throws IOException;
 
 	String readFileType(String path) throws IOException;
@@ -53,4 +65,24 @@
 	default String toRelativePath(String absolutePath) {
 		return absolutePath;
 	}
+
+
+	private BrowseResult browseNearestAccessible(String path) throws IOException {
+		try {
+			return new BrowseResult(path, parentPath(path), listDirectory(path));
+		} catch (NoSuchFileException e) {
+			String parent = parentPath(path);
+			return parent.isEmpty() ? new BrowseResult("", "", listRoots()) : browseNearestAccessible(parent);
+		}
+	}
+
+	private static String parentPath(String path) {
+		String normalized = path.replace('/', '\\');
+		if (normalized.matches("[a-zA-Z]:[/\\\\]?")) return "";
+		int lastSep = normalized.lastIndexOf('\\');
+		if (lastSep < 0) return "";
+		String parent = normalized.substring(0, lastSep);
+		if (parent.matches("[a-zA-Z]:")) return parent + "\\";
+		return parent;
+	}
 }

src/main/java/org/frankframework/flow/filesystem/FilesystemController.java

@@ -2,7 +2,6 @@
 
 import java.io.IOException;
 import java.nio.file.AccessDeniedException;
-import java.util.List;
 import java.util.Map;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
@@ -22,21 +21,13 @@ public FilesystemController(FileSystemStorage fileSystemStorage) {
 	}
 
 	@GetMapping("/browse")
-	public ResponseEntity<List<FilesystemEntry>> browse(@RequestParam(required = false, defaultValue = "") String path)
+	public ResponseEntity<BrowseResult> browse(@RequestParam(required = false, defaultValue = "") String path)
 			throws IOException {
-
-		List<FilesystemEntry> entries;
-		if (path.isBlank()) {
-			entries = fileSystemStorage.listRoots();
-		} else {
-			try {
-				entries = fileSystemStorage.listDirectory(path);
-			} catch (AccessDeniedException e) {
-				return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
-			}
+		try {
+			return ResponseEntity.ok(fileSystemStorage.browse(path));
+		} catch (AccessDeniedException e) {
+			return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
 		}
-
-		return ResponseEntity.ok(entries);
 	}
 
 	@GetMapping("/default-path")