Problem with UploadedFile::fake() and PHPUnit test - Unable to find a file at path

I keep getting "Unable to find a file at path [photoA.jpg]. Failed asserting that false is true." when trying to test image upload.

my controller store method:

public function store(Request $request)
    {
        $validatedData = $request->validate([
            'title' => 'required | max:100',
            'description' => 'required',
            'image' => 'required | image | max:1000',
            'excerpt' => 'required | max:200'
        ]);

        $post = Post::create([
            'title' => request('title'),
            'description' => request('description'),
            'image' => $request->file('image')->store('images/blog_posts', 'public'),
            'excerpt' => request('excerpt')
        ]);
        return redirect()->route('manage.posts.show', $post)
                        ->with('success', 'Your post has been successfully created!');
    }

my test:

public function it_can_upload_post_image()
    {
        Storage::fake('local');

        $manager = factory(User::class)
                    ->states('manager')
                    ->create();

        $this->actingAs($manager)->post(route('manage.posts.store'), [
            'title' => 'Post title A',
            'slug' => 'post-title-a',
            'image' => UploadedFile::fake()->image('photoA.jpg'),
            'excerpt' => 'Excerpt for post A',
            'description' => 'Description for post A'
        ]);
        Storage::disk('local')->assertExists('photoA.jpg');
    }

what am I missing? Thank you in advance!