FEATURE: Allow tutorials to declare prerequisite before it starts.

plugins/discourse-narrative-bot/lib/discourse_narrative_bot/advanced_user_narrative.rb

@@ -74,7 +74,7 @@ module DiscourseNarrativeBot
           action: :reply_to_topic_notification_level_changed
         },
         reply: {
-          next_state: :tutorial_notification_level,
+          next_state: :tutorial_change_topic_notification_level,
           action: :missing_topic_notification_level_change
         }
       },

plugins/discourse-narrative-bot/lib/discourse_narrative_bot/base.rb

@@ -19,6 +19,21 @@ module DiscourseNarrativeBot
 
         begin
           opts = transition
+
+          loop do
+            next_state = opts[:next_state]
+
+            break if next_state == :end
+
+            next_opts = self.class::TRANSITION_TABLE.fetch(next_state)
+            prerequisite = next_opts[:prerequisite]
+
+            break if !prerequisite || instance_eval(&prerequisite)
+
+            [:next_state, :next_instructions].each do |key|
+              opts[key] = next_opts[key]
+            end
+          end
         rescue InvalidTransitionError
           # For given input, no transition for current state
           return

plugins/discourse-narrative-bot/lib/discourse_narrative_bot/new_user_narrative.rb

@@ -38,6 +38,7 @@ module DiscourseNarrativeBot
       },
 
       tutorial_emoji: {
+        prerequisite: Proc.new { SiteSetting.enable_emoji },
         next_state: :tutorial_mention,
         next_instructions: Proc.new {
           I18n.t("#{I18N_KEY}.mention.instructions",

plugins/discourse-narrative-bot/spec/discourse_narrative_bot/new_user_narrative_spec.rb

@@ -302,6 +302,29 @@ describe DiscourseNarrativeBot::NewUserNarrative do
             expect(narrative.get_data(user)[:state].to_sym).to eq(:tutorial_emoji)
           end
         end
+
+        describe 'when emoji is disabled' do
+          before do
+            SiteSetting.enable_emoji = false
+          end
+
+          it 'should create the right reply' do
+            post.update!(raw: 'https://en.wikipedia.org/wiki/ROT13')
+
+            narrative.input(:reply, user, post: post)
+            new_post = Post.last
+
+            expected_raw = <<~RAW
+              #{I18n.t('discourse_narrative_bot.new_user_narrative.onebox.reply', base_uri: '')}
+
+              #{I18n.t('discourse_narrative_bot.new_user_narrative.mention.instructions',
+                discobot_username: discobot_user.username, base_uri: ''
+              )}
+            RAW
+
+            expect(new_post.raw).to eq(expected_raw.chomp)
+            expect(narrative.get_data(user)[:state].to_sym).to eq(:tutorial_mention)
+          end
         end
 
         it 'should create the right reply' do
@@ -321,6 +344,7 @@ describe DiscourseNarrativeBot::NewUserNarrative do
           expect(narrative.get_data(user)[:state].to_sym).to eq(:tutorial_emoji)
         end
       end
+    end
 
     describe 'images tutorial' do
       let(:post_2) { Fabricate(:post, topic: topic) }
@@ -585,7 +609,6 @@ describe DiscourseNarrativeBot::NewUserNarrative do
             expect(new_post.raw).to include("/forum/images")
           end
         end
-      end
 
         it 'should create the right reply' do
           post.update!(
@@ -606,6 +629,7 @@ describe DiscourseNarrativeBot::NewUserNarrative do
           expect(narrative.get_data(user)[:state].to_sym).to eq(:tutorial_images)
         end
       end
+    end
 
     describe 'emoji tutorial' do
       before do