fix(curriculum): Make recipe page test for invalid image URLs (#59338)

Co-authored-by: Ilenia <26656284+ilenia-magoni@users.noreply.github.com>

curriculum/challenges/english/25-front-end-development/lab-recipe-page/668f08ea07b99b1f4a91acab.md

@@ -147,7 +147,26 @@ assert.exists(document.querySelector('img'));
 All your `img` elements should have a valid `src` attribute and value.
 
 ```js
-assert.isAbove(document.querySelector('img')?.src.length, 0);
+const img = document.querySelector('img');
+const rawSrc = img?.getAttribute('src');
+const resolvedSrc = img?.src;
+const re = new RegExp(window.location.href, "ig");
+
+assert.isAbove(rawSrc?.trim().length, 0, "The 'src' attribute must be explicitly set.");
+assert.notMatch(resolvedSrc, re, "The 'src' should not start with the current page URL");
+
+img.onload = () => {
+  console.log('Image loaded successfully.');
+};
+
+img.onerror = (error) => {
+  console.error('Image failed to load:', error);
+  assert.fail("Your image's URL should be valid."); // Make the test instafail
+};
+
+if (img.complete) {
+  img.onload && img.onload();
+};
 ```
 
 All your `img` elements should have an `alt` attribute to describe the image.