Prevent upvoting or downvoting multiple times on the same restroom

app/controllers/restrooms_controller.rb

@@ -39,9 +39,9 @@ def create
 
   def update
     if params[:restroom][:downvote]
-      Restroom.increment_counter(:downvote, @restroom.id)
+      _vote_for_restroom(:downvote)
     elsif params[:restroom][:upvote]
-      Restroom.increment_counter(:upvote, @restroom.id)
+      _vote_for_restroom(:upvote)
     elsif @restroom.update(permitted_params)
       flash[:notice] = I18n.t('restroom.flash.updated')
     else
@@ -76,6 +76,15 @@ def find_restroom
     @restroom = Restroom.find(params[:id])
   end
 
+  def _vote_for_restroom(up_or_downvote)
+    if session[:voted_for] and session[:voted_for].include? @restroom.id
+      flash[:notice] = I18n.t('restroom.flash.alreadyvoted')
+    else
+      Restroom.increment_counter(up_or_downvote, @restroom.id)
+      session[:voted_for] = session[:voted_for] ? session[:voted_for].push(@restroom.id) : [@restroom.id]
+    end
+  end
+
   def permitted_params
     params.require(:restroom).permit(
       :name,

config/locales/en/restroom.en.yml

@@ -45,6 +45,7 @@ en:
       upvotesuccess: 'This restroom has been upvoted! Thank you for contributing to our community.'
       downvoteerror: 'There was an unexpected problem downvoting this post.'
       downvotesuccess: 'This restroom has been downvoted! Thank you for contributing to our community.'
+      alreadyvoted: 'You have already voted for this restroom.'
       new: 'A new restroom entry has been created for %{name}.'
       updated: 'This restroom entry has been updated'
       deleted: 'This restroom entry has been deleted'

config/locales/es/restroom.es.yml

@@ -45,6 +45,7 @@ es:
       upvotesuccess: '¡Este baño se ha calificado en positivo! Gracias por contribuir a nuestra comunidad.'
       downvoteerror: 'Se generó un problema inesperado con su calificación negativa.'
       downvotesuccess: '¡Este baño se ha calificado en negativo! Gracias por contribuir a nuestra comunidad.'
+      alreadyvoted: 'Ya calificó a este baño.'
       new: 'Una nueva entrada de baño se ha creado para %{name}.'
       updated: 'Esta entrada de baño ha sido actualizada'
       deleted: 'Esta entrada de baño ha sido borrada'

spec/controllers/restrooms_controller_spec.rb

@@ -8,31 +8,62 @@
 
   context "voting" do
     let(:restroom) { FactoryBot.create(:restroom) }
-
-    it "should downvote" do
-      post_params = {
+    let(:post_params_downvote) {
+      {
         id: restroom.id,
         restroom: {
           downvote: true
         }
       }
+    }
+    let(:post_params_upvote) {
+      {
+        id: restroom.id,
+        restroom: {
+          upvote: true
+        }
+      }
+    }
 
+    it "should downvote" do
       expect {
-        post :update, params: post_params
+        post :update, params: post_params_downvote
       }.to change { restroom.reload.downvote }.by 1
     end
 
     it "should upvote" do
+      expect {
+        post :update, params: post_params_upvote
+      }.to change { restroom.reload.upvote }.by 1
+    end
+
+    it "shouldn't upvote or downvote twice" do
+      post :update, params: post_params_upvote
+
+      expect {
+        post :update, params: post_params_upvote
+      }.not_to change { restroom.reload.upvote }
+
+      expect {
+        post :update, params: post_params_downvote
+      }.not_to change { restroom.reload.downvote }
+    end
+
+    it "should allow you to vote for multiple restrooms" do
+      session[:voted_for] = [restroom.id]
+      restroom_two = FactoryBot.create(:restroom)
+
       post_params = {
-        id: restroom.id,
+        id: restroom_two.id,
         restroom: {
-          upvote: true
+          downvote: true
         }
       }
 
       expect {
         post :update, params: post_params
-      }.to change { restroom.reload.upvote }.by 1
+      }.to change { restroom_two.reload.downvote }.by 1
+      expect(session[:voted_for]).to match_array([restroom.id, restroom_two.id])
     end
   end
 end