Implement one-click-unsubscribe (#192)

* Implement one-click-unsubscribe feature WIP

* Adjust email subscription page's css

* Add mobile scss

* Apply subscription logic to other email type

* Add back default email footer

* Create EmailSubscriptions request spec

app/assets/stylesheets/email_subscriptions.scss

@@ -0,0 +1,20 @@
+.unsubscribed {
+  background: #66e2d5;
+  color: white;
+  margin: 100px auto;
+  padding: 40px 10px;
+
+  @media screen and (min-width: 550px) {
+    margin: 100px auto;
+    width: 450px;
+    padding: 40px;
+  }
+}
+
+.unsubscribed__title {
+  font-weight: 600;
+}
+
+.unsubscribed__message {
+  font-weight: 300;
+}

app/assets/stylesheets/minimal.scss

@@ -29,3 +29,5 @@
 
 @import 'chat';
 @import 'livechat/chat';
+
+@import 'email_subscriptions';

app/controllers/email_subscriptions_controller.rb

@@ -0,0 +1,14 @@
+class EmailSubscriptionsController < ApplicationController
+  def unsubscribe
+    verified_params = Rails.application.message_verifier(:unsubscribe).verify(params[:ut])
+
+    if verified_params[:expires_at] > Time.now
+      user = User.find(verified_params[:user_id])
+      user.update(verified_params[:email_type] => false)
+    else
+      not_found
+    end
+  rescue ActiveSupport::MessageVerifier::InvalidSignature
+    not_found
+  end
+end

app/labor/email_digest.rb

@@ -17,9 +17,11 @@ class EmailDigest
       user_email_heuristic = EmailLogic.new(user).analyze
       next unless user_email_heuristic.should_receive_email?
       articles = user_email_heuristic.articles_to_send
-      DigestMailer.digest_email(user, articles).deliver
-    rescue
-      puts "Email issue"
+      begin
+        DigestMailer.digest_email(user, articles).deliver
+      rescue StandardError
+        puts "Email issue"
+      end
     end
   end
 

app/mailers/application_mailer.rb

@@ -1,4 +1,12 @@
 class ApplicationMailer < ActionMailer::Base
   default from: "The DEV Community <yo@dev.to>"
-  layout 'mailer'
+  layout "mailer"
+
+  def generate_unsubscribe_token(id, email_type)
+    Rails.application.message_verifier(:unsubscribe).generate(
+      user_id: id,
+      email_type: email_type.to_sym,
+      expires_at: Time.now + 2.days,
+    )
+  end
 end

app/mailers/digest_mailer.rb

@@ -6,6 +6,7 @@ class DigestMailer < ApplicationMailer
               user
             end
     @articles = articles.first(6)
+    @unsubscribe = generate_unsubscribe_token(@user.id, :email_digest_periodic)
     @digest_email = true
     mail(from: "DEV Digest <yo@dev.to>", to: @user.email, subject: "#{adjusted_title(@articles.first)} + #{@articles.size - 1} #{email_end_phrase} #{random_emoji}") do |format|
       format.html { render "layouts/mailer" }
@@ -14,12 +15,11 @@ class DigestMailer < ApplicationMailer
 
   def adjusted_title(article)
     title = article.title.strip
-
-    title = "\"#{title}\"" unless title.start_with? '"'
+    "\"#{title}\"" unless title.start_with? '"'
   end
 
   def random_emoji
-    ["🤓","🎉","🙈","🔥","💬","👋","👏","🐶","🦁","🐙","🦄","❤️","😇"].shuffle.take(3).join
+    ["🤓", "🎉", "🙈", "🔥", "💬", "👋", "👏", "🐶", "🦁", "🐙", "🦄", "❤️", "😇"].shuffle.take(3).join
   end
 
   def email_end_phrase

app/mailers/notify_mailer.rb

@@ -7,6 +7,7 @@ class NotifyMailer < ApplicationMailer
       comment.parent_user
     end
     return if RateLimitChecker.new.limit_by_email_recipient_address(@user.email)
+    @unsubscribe = generate_unsubscribe_token(@user.id, :email_comment_notifications)
     @comment = comment
     mail(to: @user.email, subject: "#{@comment.user.name} replied to your #{@comment.parent_type}") do |format|
       format.html { render "layouts/mailer" }
@@ -22,6 +23,7 @@ class NotifyMailer < ApplicationMailer
     end
     return if RateLimitChecker.new.limit_by_email_recipient_address(@user.email)
     @follower = follow.follower
+    @unsubscribe = generate_unsubscribe_token(@user.id, :email_follower_notifications)
 
     mail(to: @user.email, subject: "#{@follower.name} just followed you on dev.to") do |format|
       format.html { render 'layouts/mailer' }
@@ -35,6 +37,7 @@ class NotifyMailer < ApplicationMailer
     @mentioner = User.find(mention.mentionable.user_id)
     @mentionable = mention.mentionable
     @mention = mention
+    @unsubscribe = generate_unsubscribe_token(@user.id, :email_mention_notifications)
 
     mail(to: @user.email, subject: "#{@mentioner.name} just mentioned you!") do |format|
       format.html { render 'layouts/mailer' }
@@ -50,6 +53,7 @@ class NotifyMailer < ApplicationMailer
     end
     return if RateLimitChecker.new.limit_by_email_recipient_address(@user.email)
     @unread_notifications_count = NotificationCounter.new(@user).unread_notification_count
+    @unsubscribe = generate_unsubscribe_token(@user.id, :email_unread_notifications)
     mail(to: @user.email, subject: "🔥 You have #{@unread_notifications_count} unread notifications on dev.to") do |format|
       format.html { render 'layouts/mailer' }
       format.text { render plain: "Visit https://dev.to/notifications to read all of your notifications" }

app/views/email_subscriptions/unsubscribe.html.erb

@@ -0,0 +1,10 @@
+<div class="unsubscribed">
+  <div class="unsubscribed__title">
+    You have been successfully unsubscribed. 😔
+  </div>
+  <br/>
+  <div class="unsubscribed__message">
+    If that was a mistake or you would like to update other email preferences,
+    <a href="https://dev.to/settings/notifications">click here</a>.
+  </div>
+</div>

app/views/layouts/_mailer_content.html.erb

@@ -219,5 +219,4 @@
       <% end %>
     </em>
   </center>
-
 <% end %>

app/views/layouts/mailer.html.erb

@@ -8,7 +8,11 @@
       </tr>
       <tr>
         <td style="padding:3% 12% 2% 4%;font-size:16px;line-height:22px;color:#7d7d7d">
-          Don't want to get emails like this? Adjust your email settings at <a href="https://dev.to/settings/notifications">dev.to/settings/notifications</a>
+          <%if @unsubscribe %>
+            <%= link_to "Unsubscribe", email_subscriptions_unsubscribe_url(ut: @unsubscribe) %> | <a href="https://dev.to/settings/notifications">Adjust your email settings</a>
+          <% else %>
+            Don't want to get emails like this? Adjust your email settings at <a href="https://dev.to/settings/notifications">dev.to/settings/notifications</a>
+          <% end %>
           <br/><br/>
           <% if @user.twitter_username.blank? %>
             Reminder: You used <b>GitHub</b> to authenticate your account, so use that to sign in if prompted.

config/routes.rb

@@ -91,6 +91,7 @@ Rails.application.routes.draw do
   resources :additional_content_boxes, only: [:index]
   get "/notifications/:username" => "notifications#index"
   patch "/onboarding_update" => "users#onboarding_update"
+  get "email_subscriptions/unsubscribe"
   # resources :users
 
   ### Subscription vanity url

spec/requests/email_subscriptions_spec.rb

@@ -0,0 +1,39 @@
+require "rails_helper"
+
+RSpec.describe "EmailSubscriptions", type: :request do
+  let(:user) { create(:user) }
+
+  def generate_token(user_id)
+    Rails.application.message_verifier(:unsubscribe).generate(
+      user_id: user_id,
+      email_type: :email_mention_notifications,
+      expires_at: Time.now + 2.days,
+    )
+  end
+
+  describe "GET /email_subscriptions/unsubscribe" do
+    it "returns 200 if valid" do
+      get email_subscriptions_unsubscribe_url(ut: generate_token(user.id))
+      expect(response.status).to be(200)
+    end
+
+    it "does unsubscribe the user" do
+      get email_subscriptions_unsubscribe_url(ut: generate_token(user.id))
+      user.reload
+      expect(user.email_mention_notifications).to be(false)
+    end
+
+    it "handles error properly" do
+      expect { get email_subscriptions_unsubscribe_url }.
+        to raise_error(ActionController::RoutingError)
+    end
+
+    it "won't work if it's past expireation date" do
+      token = generate_token(user.id)
+      Timecop.freeze(Date.today + 3) do
+        expect { get email_subscriptions_unsubscribe_url(ut: token) }.
+          to raise_error(ActionController::RoutingError)
+      end
+    end
+  end
+end