Delete duplicate records in different languages

app/lib/poll_option_finder.rb

@@ -0,0 +1,31 @@
+class PollOptionFinder
+  attr_reader :question
+
+  def initialize(question)
+    @question = question
+  end
+
+  def manageable_choices
+    choices_map.select { |choice, ids| ids.count == 1 }
+  end
+
+  def unmanageable_choices
+    choices_map.reject { |choice, ids| ids.count == 1 }
+  end
+
+  private
+
+    def choices_map
+      @choices_map ||= existing_choices.to_h do |choice|
+        [choice, options.where("lower(title) = lower(?)", choice).distinct.ids]
+      end
+    end
+
+    def options
+      question.question_options.joins(:translations).reorder(:id)
+    end
+
+    def existing_choices
+      question.answers.where(option_id: nil).distinct.pluck(:answer)
+    end
+end

lib/tasks/polls.rake

@@ -37,26 +37,35 @@ namespace :polls do
     logger.info "Removing duplicate answers in polls"
 
     Tenant.run_on_each do
-      duplicate_ids = Poll::Answer.where(option_id: nil)
-                                  .select(:question_id, :author_id, :answer)
-                                  .group(:question_id, :author_id, :answer)
-                                  .having("count(*) > 1")
-                                  .pluck(:question_id, :author_id, :answer)
+      Poll::Question.find_each do |question|
+        manageable_titles = PollOptionFinder.new(question).manageable_choices.keys
 
-      duplicate_ids.each do |question_id, author_id, answer|
-        poll_answers = Poll::Answer.where(question_id: question_id, author_id: author_id, answer: answer)
+        question.question_options.each do |option|
+          titles = option.translations.where(title: manageable_titles).select(:title).distinct
 
-        poll_answers.excluding(poll_answers.first).each do |poll_answer|
-          poll_answer.delete
+          author_ids = question.answers
+                               .where(answer: titles)
+                               .select(:author_id)
+                               .group(:author_id)
+                               .having("count(*) > 1")
+                               .pluck(:author_id)
 
-          tenant_info = " on tenant #{Tenant.current_schema}" unless Tenant.default?
-          log_message = "Deleted duplicate record with ID #{poll_answer.id} " \
-                        "from the #{Poll::Answer.table_name} table " \
-                        "with question_id #{question_id}, " \
-                        "author_id #{author_id} " \
-                        "and answer #{answer}" + tenant_info.to_s
-          logger.info(log_message)
-          duplicate_records_logger.info(log_message)
+          author_ids.each do |author_id|
+            poll_answers = question.answers.where(option_id: nil, answer: titles, author_id: author_id)
+
+            poll_answers.excluding(poll_answers.first).each do |poll_answer|
+              poll_answer.delete
+
+              tenant_info = " on tenant #{Tenant.current_schema}" unless Tenant.default?
+              log_message = "Deleted duplicate record with ID #{poll_answer.id} " \
+                            "from the #{Poll::Answer.table_name} table " \
+                            "with question_id #{question.id}, " \
+                            "author_id #{author_id} " \
+                            "and answer #{poll_answer.answer}" + tenant_info.to_s
+              logger.info(log_message)
+              duplicate_records_logger.info(log_message)
+            end
+          end
         end
       end
     end
@@ -76,20 +85,13 @@ namespace :polls do
       end
 
       questions.each do |question|
-        options = question.question_options.joins(:translations).reorder(:id)
-        existing_choices = question.answers.where(option_id: nil).distinct.pluck(:answer)
+        option_finder = PollOptionFinder.new(question)
 
-        choices_map = existing_choices.to_h do |choice|
-          [choice, options.where("lower(title) = lower(?)", choice).distinct.ids]
-        end
-
-        manageable_choices, unmanageable_choices = choices_map.partition { |choice, ids| ids.count == 1 }
-
-        manageable_choices.each do |choice, ids|
+        option_finder.manageable_choices.each do |choice, ids|
           question.answers.where(option_id: nil, answer: choice).update_all(option_id: ids.first)
         end
 
-        unmanageable_choices.each do |choice, ids|
+        option_finder.unmanageable_choices.each do |choice, ids|
           tenant_info = " on tenant #{Tenant.current_schema}" unless Tenant.default?
 
           if ids.count == 0

spec/lib/tasks/polls_spec.rb

@@ -94,6 +94,40 @@ describe "polls tasks" do
       expect(Poll::Answer.count).to eq 2
     end
 
+    it "removes duplicate answers in different languages" do
+      question = create(:poll_question_multiple, max_votes: 2)
+
+      create(:poll_question_option, question: question, title_en: "Yes", title_de: "Ja")
+      create(:poll_question_option, question: question, title_en: "No", title_de: "Nein")
+      create(:poll_question_option, question: question, title_en: "Maybe", title_de: "Vielleicht")
+
+      create(:poll_answer, author: user, question: question, answer: "Yes", option: nil)
+      create(:poll_answer, author: user, question: question, answer: "Ja", option: nil)
+
+      expect(Poll::Answer.count).to eq 2
+
+      Rake.application.invoke_task("polls:remove_duplicate_answers")
+
+      expect(Poll::Answer.count).to eq 1
+    end
+
+    it "does not remove duplicate answers when many options are possible" do
+      question = create(:poll_question_multiple, title: "How do you pronounce it?", max_votes: 2)
+
+      create(:poll_question_option, question: question, title_en: "A", title_es: "EI")
+      create(:poll_question_option, question: question, title_en: "E", title_es: "I")
+      create(:poll_question_option, question: question, title_en: "I", title_es: "AI")
+
+      create(:poll_answer, question: question, author: user, answer: "I", option: nil)
+      create(:poll_answer, question: question, author: user, answer: "AI", option: nil)
+
+      expect(Poll::Answer.count).to eq 2
+
+      Rake.application.invoke_task("polls:remove_duplicate_answers")
+
+      expect(Poll::Answer.count).to eq 2
+    end
+
     it "removes duplicate answers on tenants" do
       create(:tenant, schema: "answers")
 
@@ -176,6 +210,11 @@ describe "polls tasks" do
       user = create(:user, :level_two)
       question = create(:poll_question_multiple, :abc)
 
+      localized_question = create(:poll_question_multiple)
+      create(:poll_question_option, question: localized_question, title_en: "Yes", title_de: "Ja")
+      create(:poll_question_option, question: localized_question, title_en: "No", title_de: "Nein")
+      create(:poll_question_option, question: localized_question, title_en: "Maybe", title_de: "Vielleicht")
+
       answer_attributes = {
         question_id: question.id,
         author_id: user.id,
@@ -185,14 +224,23 @@ describe "polls tasks" do
       answer = create(:poll_answer, answer_attributes)
       insert(:poll_answer, answer_attributes)
 
+      localized_answer_attributes = { author: user, question: localized_question, option: nil }
+      localized_answer = create(:poll_answer, localized_answer_attributes.merge(answer: "Yes"))
+      create(:poll_answer, localized_answer_attributes.merge(answer: "Ja"))
+
       answer.reload
+      localized_answer.reload
+
       expect(answer.option_id).to be nil
+      expect(localized_answer.option_id).to be nil
 
       Rake.application.invoke_task("polls:populate_option_id")
       answer.reload
+      localized_answer.reload
 
-      expect(Poll::Answer.count).to eq 1
+      expect(Poll::Answer.count).to eq 2
       expect(answer.option_id).to eq question.question_options.find_by(title: "Answer A").id
+      expect(localized_answer.option_id).to eq localized_question.question_options.find_by(title: "Yes").id
     end
 
     it "populates the option_id column on tenants" do