#399

frontend/src/components/posts/PostThumbnailPreview.test.tsx

@@ -1,4 +1,4 @@
-import { render, screen } from '@testing-library/react'
+import { fireEvent, render, screen } from '@testing-library/react'
 import { describe, expect, it } from 'vitest'
 
 import PostThumbnailPreview from '@/components/posts/PostThumbnailPreview'
@@ -9,4 +9,28 @@ describe ('PostThumbnailPreview', () => {
 
     expect (screen.getByRole ('img')).toHaveAttribute ('src', 'blob:preview')
   })
+
+  it ('renders an empty thumbnail frame without text when the URL is empty', () => {
+    const { container } = render (
+        <PostThumbnailPreview url="" className="h-10 w-10"/>)
+
+    expect (screen.queryByRole ('img')).toBeNull ()
+    expect (screen.queryByText ('サムネールを表示できません')).toBeNull ()
+    expect (screen.queryByText ('なし')).toBeNull ()
+    expect (container.querySelector ('div.rounded.border.bg-muted')).not.toBeNull ()
+    expect (container.textContent).toBe ('')
+  })
+
+  it ('renders an empty thumbnail frame without text when image loading fails', () => {
+    const { container } = render (
+        <PostThumbnailPreview url="blob:preview" className="h-10 w-10"/>)
+
+    fireEvent.error (screen.getByRole ('img'))
+
+    expect (screen.queryByRole ('img')).toBeNull ()
+    expect (screen.queryByText ('サムネールを表示できません')).toBeNull ()
+    expect (screen.queryByText ('なし')).toBeNull ()
+    expect (container.querySelector ('div.rounded.border.bg-muted')).not.toBeNull ()
+    expect (container.textContent).toBe ('')
+  })
 })