fixed not use jsdom File object

Author: HillLiu

packages/lib/ajax-save/package.json

@@ -1,5 +1,5 @@
 {
-  "version": "0.1.3",
+  "version": "0.1.4",
   "name": "ajax-save",
   "repository": {
     "type": "git",

packages/lib/ajax-save/src/__tests__/readUploadTest.js

@@ -3,10 +3,12 @@ import { expect } from "chai";
 import readUpload from "../readUpload";
 
 describe("Test readUpload", () => {
+  beforeEach(() => {
+    global.File = window.File;
+  });
   it("test read upload", async () => {
-    document.body.innerHTML = '<input type="file">';
-    const simFile = new File(["FOO"], "foo.txt");
-    const fileContent = await readUpload(simFile);
+    const fakeFile = new File(["FOO"], "foo.txt", { type: "text/plain" });
+    const fileContent = await readUpload(fakeFile);
     expect(fileContent).to.equal("FOO");
   });
 });