According to the W3C File API specification, the File constructor requires 2 (or 3) parameters.
So to create a empty file do:
var f = new File([""], "filename");
- The first argument is the data provided as an array of lines of text;
- The second argument is the filename ;
-
The third argument looks like:
var f = new File([""], "filename.txt", {type: "text/plain", lastModified: date})
It works in FireFox, Chrome and Opera, but not in Safari or IE/Edge.