Add test for Account#save_with_optional_media! (#5603)

There was a test when some of the properties are invalid, but none when all
of them are valid.

spec/models/account_spec.rb

@@ -93,23 +93,46 @@ RSpec.describe Account, type: :model do
   end
 
   describe '#save_with_optional_media!' do
-    it 'sets default avatar, header, avatar_remote_url, and header_remote_url if some of them are invalid' do
+    before do
       stub_request(:get, 'https://remote/valid_avatar').to_return(request_fixture('avatar.txt'))
       stub_request(:get, 'https://remote/invalid_avatar').to_return(request_fixture('feed.txt'))
-      account = Fabricate(:account,
+    end
+
+    let(:account) do
+      Fabricate(:account,
                 avatar_remote_url: 'https://remote/valid_avatar',
                 header_remote_url: 'https://remote/valid_avatar')
+    end
 
+    let!(:expectation) { account.dup }
+
+    context 'with valid properties' do
+      before do
+        account.save_with_optional_media!
+      end
+
+      it 'unchanges avatar, header, avatar_remote_url, and header_remote_url' do
+        expect(account.avatar_remote_url).to eq expectation.avatar_remote_url
+        expect(account.header_remote_url).to eq expectation.header_remote_url
+        expect(account.avatar_file_name).to  eq expectation.avatar_file_name
+        expect(account.header_file_name).to  eq expectation.header_file_name
+      end
+    end
+
+    context 'with invalid properties' do
+      before do
         account.avatar_remote_url = 'https://remote/invalid_avatar'
         account.save_with_optional_media!
+      end
 
-      account.reload
+      it 'sets default avatar, header, avatar_remote_url, and header_remote_url' do
         expect(account.avatar_remote_url).to eq ''
         expect(account.header_remote_url).to eq ''
         expect(account.avatar_file_name).to  eq nil
         expect(account.header_file_name).to  eq nil
       end
     end
+  end
 
   describe '#subscribed?' do
     it 'returns false when no subscription expiration information is present' do