Add test for design item using imageV432x230

Test that, when imageV432x230 is provided,
it is used.

Also slightly reorganises the tests for better readability

ee/spec/frontend/design_management/components/list/item_spec.js

@@ -17,6 +17,7 @@ const DESIGN_VERSION_EVENT = {
 
 describe('Design management list item component', () => {
   let wrapper;
+
   function createComponent({
     notesCount = 0,
     event = DESIGN_VERSION_EVENT.NO_CHANGE,
@@ -48,17 +49,39 @@ describe('Design management list item component', () => {
     wrapper.destroy();
   });
 
-  it('renders an image when it appears in view', () => {
-    createComponent();
-    const image = wrapper.find('img');
+  describe('when item is not in view', () => {
+    it('image is not rendered', () => {
+      createComponent();
+
+      const image = wrapper.find('img');
+      expect(image.attributes('src')).toBe('');
+    });
+  });
 
-    expect(image.attributes('src')).toBe('');
+  describe('when item appears in view', () => {
+    beforeEach(() => {
+      createComponent();
 
-    wrapper.find(GlIntersectionObserver).vm.$emit('appear');
+      wrapper.find(GlIntersectionObserver).vm.$emit('appear');
+      return wrapper.vm.$nextTick();
+    });
 
-    return wrapper.vm.$nextTick().then(() => {
+    it('renders an image', () => {
+      const image = wrapper.find('img');
       expect(image.attributes('src')).toBe('http://via.placeholder.com/300');
     });
+
+    describe('when imageV432x230 and image provided', () => {
+      it('renders imageV432x230 image', () => {
+        const mockSrc = 'mock-imageV432x230-url';
+        wrapper.setProps({ imageV432x230: mockSrc });
+
+        return wrapper.vm.$nextTick().then(() => {
+          const image = wrapper.find('img');
+          expect(image.attributes('src')).toBe(mockSrc);
+        });
+      });
+    });
   });
 
   describe('with notes', () => {