fix #695 mark isfs root bad if unreachable

Author: gjsjohnmurray

src/providers/FileSystemProvider/FileSystemProvider.ts

@@ -46,7 +46,7 @@ export class FileSystemProvider implements vscode.FileSystemProvider {
     const parent = await this._lookupAsDirectory(uri);
     const api = new AtelierAPI(uri);
     if (!api.active) {
-      return;
+      throw vscode.FileSystemError.Unavailable(`${uri.toString()} is unavailable`);
     }
     const sql = `CALL %Library.RoutineMgr_StudioOpenDialog(?,?,?,?,?,?,?)`;
     const { query } = url.parse(uri.toString(true), true);
@@ -293,6 +293,12 @@ export class FileSystemProvider implements vscode.FileSystemProvider {
 
   // Fetch entry (a file or directory) from cache, else from server
   private async _lookup(uri: vscode.Uri): Promise<Entry> {
+    if (uri.path === "/") {
+      const api = new AtelierAPI(uri);
+      if (!api.active) {
+        throw vscode.FileSystemError.Unavailable(`${uri.toString()} is unavailable`);
+      }
+    }
     const parts = uri.path.split("/");
     let entry: Entry = this.root;
     for (let i = 0; i < parts.length; i++) {