add test setup

Author: Awakich

test-setup.ts

@@ -14,4 +14,18 @@ if (!Element.prototype.scrollTo) {
   (Element.prototype as any).scrollTo = function () {};
 }
 
+if (!URL.createObjectURL) {
+  let counter = 0;
+  const objectURLs = new Map<string, string>();
+  (URL as any).createObjectURL = function (blob: Blob): string {
+    const id = `blob:${++counter}`;
+    const url = `blob:${id}`;
+    objectURLs.set(url, blob as any);
+    return url;
+  };
+  (URL as any).revokeObjectURL = function (url: string): void {
+    objectURLs.delete(url);
+  };
+}
+
 setupTestBed();