test: add testing cases

Author: EscapedGibbon

src/load/__tests__/fetchURL.test.ts

@@ -0,0 +1,30 @@
+import { encodeDataURL } from '../../save/encodeDataURL.js';
+import { fetchURL } from '../fetchURL.js';
+
+describe('testing fetchURL', () => {
+  test('basic test 1', async () => {
+    const image = await fetchURL(
+      'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAAAAACoBHk5AAAAFklEQVR4XmNggID///+DSCCEskHM/wCAnQr2TY5mOAAAAABJRU5ErkJggg==',
+    );
+    expect(image.bitDepth).toBe(8);
+    expect(image.getRawImage().data).toEqual(
+      new Uint8Array([
+        0, 0, 0, 0, 0, 0, 255, 255, 255, 0, 0, 255, 0, 255, 0, 0, 255, 255, 255,
+        0, 255, 0, 255, 0, 255,
+      ]),
+    );
+  });
+  test('encoded URL must be equal to decoded one', async () => {
+    const dataURL =
+      'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAAAAACoBHk5AAAAFklEQVR4XmNggID///+DSCCEskHM/wCAnQr2TY5mOAAAAABJRU5ErkJggg==';
+    const image = await fetchURL(dataURL);
+    const result = encodeDataURL(image);
+    expect(result).toEqual(dataURL);
+  });
+  test('decode from an image url', async () => {
+    const image = await fetchURL('https://picsum.photos/id/237/150/200');
+    expect(image.width).toEqual(150);
+    expect(image.height).toEqual(200);
+    expect(image.bitDepth).toEqual(8);
+  });
+});