How to make a test for image file?

I have this code to store a new post (it's work as testing manually)

public function store(PostRequest $request, Post $post)
{
    $data = $request->validated();
    
    $request->image->store('post_images');

    $data['image'] = $request->image->hashName();

    $post->create($data);

    return redirect()->route('posts.index');
}

My test:

/** @test */
public function an_admin_can_add_a_new_post()
{
    $admin = User::factory()->create(['is_admin' => true]);

    Storage::fake('public');

    $this->actingAs($admin)
        ->post(route('posts.store'), [
            'title' => 'how to write a clean code',
            'desc' => 'description of the post',
            'image' => $file = UploadedFile::fake()->image('post.jpg'),
            'tag_id' => Tag::factory()->create()->id,
        ]);

    Storage::assertExists('post_images/' . $file->hashName());

    $this->assertDatabaseCount('posts', 1);
}

The test is passed but I'm have feeling that this is not the correct way for testing image!

Please correct me if I'm wrong!