adding demo gif

Author: dkundel

Diff for: README.md

@@ -8,6 +8,8 @@ Before using the extension please make sure to read the [Disclaimer](#Disclaimer
 
 # How to use 
 
+![demo](images/demo.gif)
+
 1. Press the Shortcut <kbd>Cmd+Alt+N</kbd> or run the `Files: Advanced New File` command.
 
 2. Enter a relative file path or stick with the default. If you have a file open it will guess the extension based on the current extension.

Diff for: images/demo.gif

@@ -29,9 +29,8 @@ export function activate(context: ExtensionContext) {
 }
 
 export class FileController {
-  
   public showFileNameDialog(): Q.Promise<string> {
-    const currentFileName: string = window.activeTextEditor.document.fileName;
+    const currentFileName: string = window.activeTextEditor ? window.activeTextEditor.document.fileName : '';
     const ext: string = path.extname(currentFileName) || '.ts';
     const deferred: Q.Deferred<string> = Q.defer<string>();
 
@@ -55,10 +54,7 @@ export class FileController {
     let fileExists: boolean = fs.existsSync(newFileName);
 
     if (!fileExists) {
-      let err: string = mkdirp.sync(dirname);
-      if (err) {
-        deferred.reject(err);
-      }
+      mkdirp.sync(dirname);
 
       fs.appendFile(newFileName, '', (err) => {
         if (err) {