fix: validate instagram story only while saving the message (#6340)

spec/models/channel/facebook_page_spec.rb

@@ -30,6 +30,42 @@ RSpec.describe Channel::FacebookPage do
         channel.prompt_reauthorization!
       end
     end
+
+    context 'when fetch instagram story' do
+      let!(:account) { create(:account) }
+      let!(:instagram_channel) { create(:channel_instagram_fb_page, account: account, instagram_id: 'chatwoot-app-user-id-1') }
+      let!(:instagram_inbox) { create(:inbox, channel: instagram_channel, account: account, greeting_enabled: false) }
+      let(:fb_object) { double }
+      let(:message) { create(:message, inbox_id: instagram_inbox.id) }
+      let(:instagram_message) { create(:message, :instagram_story_mention, inbox_id: instagram_inbox.id) }
+
+      it '#fetch_instagram_story_link' do
+        allow(Koala::Facebook::API).to receive(:new).and_return(fb_object)
+        allow(fb_object).to receive(:get_object).and_return(
+          { story:
+            {
+              mention: {
+                link: 'https://www.example.com/test.jpeg',
+                id: '17920786367196703'
+              }
+            },
+            from: {
+              username: 'Sender-id-1', id: 'Sender-id-1'
+            },
+            id: 'instagram-message-id-1234' }.with_indifferent_access
+        )
+        story_link = instagram_channel.fetch_instagram_story_link(message)
+        expect(story_link).to eq('https://www.example.com/test.jpeg')
+      end
+
+      it '#delete_instagram_story' do
+        expect(instagram_message.attachments.count).to eq(1)
+
+        instagram_channel.delete_instagram_story(instagram_message)
+
+        expect(instagram_message.attachments.count).to eq(0)
+      end
+    end
   end
 
   it 'has a valid name' do