Remove Poll::Voter record when there is no more user answers

Now we can remove answers we should provide a way of removing voting.

app/controllers/polls/answers_controller.rb

@@ -5,7 +5,7 @@ class Polls::AnswersController < ApplicationController
                                        through_association: :answers
 
   def destroy
-    @answer.destroy!
+    @answer.destroy_and_remove_voter_participation
 
     respond_to do |format|
       format.html do

app/models/poll/answer.rb

@@ -23,6 +23,16 @@ class Poll::Answer < ApplicationRecord
     end
   end
 
+  def destroy_and_remove_voter_participation
+    transaction do
+      destroy!
+
+      if author.poll_answers.where(question_id: poll.question_ids).none?
+        Poll::Voter.find_by(user: author, poll: poll, origin: "web").destroy!
+      end
+    end
+  end
+
   private
 
     def max_votes

spec/models/poll/answer_spec.rb

@@ -106,4 +106,32 @@ describe Poll::Answer do
       expect(answer).not_to be_persisted
     end
   end
+
+  describe "#destroy_and_remove_voter_participation" do
+    let(:poll) { create(:poll) }
+    let(:question) { create(:poll_question, :yes_no, poll: poll) }
+
+    it "destroys voter record and answer when it was the only user's answer" do
+      answer = build(:poll_answer, question: question)
+      answer.save_and_record_voter_participation
+
+      expect { answer.destroy_and_remove_voter_participation }
+        .to change { Poll::Answer.count }.by(-1)
+        .and change { Poll::Voter.count }.by(-1)
+    end
+
+    it "destroys the answer but does not destroy the voter record when the user
+        has answered other poll questions" do
+      answer = build(:poll_answer, question: question)
+      answer.save_and_record_voter_participation
+      other_question = create(:poll_question, :yes_no, poll: poll)
+      other_answer = build(:poll_answer, question: other_question, author: answer.author)
+      other_answer.save_and_record_voter_participation
+
+      expect(other_answer).to be_persisted
+      expect { answer.destroy_and_remove_voter_participation }
+        .to change { Poll::Answer.count }.by(-1)
+        .and change { Poll::Voter.count }.by(0)
+    end
+  end
 end

spec/system/polls/voter_spec.rb

@@ -3,12 +3,10 @@ require "rails_helper"
 describe "Voter" do
   context "Origin", :with_frozen_time do
     let(:poll) { create(:poll) }
-    let(:question) { create(:poll_question, poll: poll) }
+    let!(:question) { create(:poll_question, :yes_no, poll: poll) }
     let(:booth) { create(:poll_booth) }
     let(:officer) { create(:poll_officer) }
     let(:admin) { create(:administrator) }
-    let!(:answer_yes) { create(:poll_question_answer, question: question, title: "Yes") }
-    let!(:answer_no) { create(:poll_question_answer, question: question, title: "No") }
 
     before do
       create(:geozone, :in_census)
@@ -29,8 +27,34 @@ describe "Voter" do
         expect(page).not_to have_button("Vote Yes")
       end
 
-      expect(Poll::Voter.count).to eq(1)
+      visit poll_path(poll)
-      expect(Poll::Voter.first.origin).to eq("web")
+
+      expect(page).to have_content("You have already participated in this poll.")
+      expect(page).to have_content("If you vote again it will be overwritten")
+    end
+
+    scenario "Remove vote via web - Standard" do
+      user = create(:user, :level_two)
+      create(:poll_answer, question: question, author: user, answer: "Yes")
+      create(:poll_voter, poll: poll, user: user)
+
+      login_as user
+      visit poll_path(poll)
+
+      expect(page).to have_content("You have already participated in this poll.")
+      expect(page).to have_content("If you vote again it will be overwritten")
+
+      within("#poll_question_#{question.id}_answers") do
+        click_button "You have voted Yes"
+
+        expect(page).to have_button("Vote Yes")
+        expect(page).to have_button("Vote No")
+      end
+
+      visit poll_path(poll)
+
+      expect(page).not_to have_content("You have already participated in this poll.")
+      expect(page).not_to have_content("If you vote again it will be overwritten")
     end
 
     scenario "Voting via web as unverified user" do
@@ -40,8 +64,8 @@ describe "Voter" do
       visit poll_path(poll)
 
       within("#poll_question_#{question.id}_answers") do
-        expect(page).to have_link(answer_yes.title, href: verification_path)
+        expect(page).to have_link("Yes", href: verification_path)
-        expect(page).to have_link(answer_no.title, href: verification_path)
+        expect(page).to have_link("No", href: verification_path)
       end
 
       expect(page).to have_content("You must verify your account in order to answer")
@@ -120,7 +144,7 @@ describe "Voter" do
 
       scenario "Trying to vote in web and then in booth" do
         login_as user
-        vote_for_poll_via_web(poll, question, answer_yes.title)
+        vote_for_poll_via_web(poll, question, "Yes")
         expect(Poll::Voter.count).to eq(1)
 
         click_link "Sign out"
@@ -147,7 +171,7 @@ describe "Voter" do
         visit poll_path(poll)
 
         within("#poll_question_#{question.id}_answers") do
-          expect(page).not_to have_button(answer_yes.title)
+          expect(page).not_to have_button("Yes")
         end
         expect(page).to have_content "You have already participated in a physical booth. You can not participate again."
         expect(Poll::Voter.count).to eq(1)
@@ -186,7 +210,7 @@ describe "Voter" do
       visit poll_path(poll)
 
       within("#poll_question_#{question.id}_answers") do
-        expect(page).not_to have_button(answer_yes.title)
+        expect(page).not_to have_button("Yes")
       end
 
       expect(page).to have_content "You have already participated in a physical booth. You can not participate again."