Create gdz file on the fly in test

src/datasource/load_data.spec.ts

@@ -1,5 +1,6 @@
 import {describe, expect, it} from '@jest/globals';
-import {Blob} from 'buffer';
+import {Blob, Buffer} from 'buffer';
+import {zipSync} from 'fflate';
 import {readFileSync} from 'fs';
 import {loadFile} from './load_data';
 
@@ -17,8 +18,11 @@ describe('loadFile', () => {
   });
 
   it('loads GEDZIP file', async () => {
-    const file = readFileSync('src/datasource/testdata/test.gdz');
-    const blob = new Blob([file]) as globalThis.Blob;
+    const file = zipSync({
+      'test.ged': readFileSync('src/datasource/testdata/test.ged'),
+      'topola.jpg': readFileSync('src/datasource/testdata/topola.jpg'),
+    });
+    const blob = new Blob([Buffer.from(file)]) as globalThis.Blob;
     const {gedcom, images} = await loadFile(blob);
     expect(gedcom.length).toBe(4408);
     expect(images.size).toBe(1);