discourse/spec/services/post_alerter_spec.rb

# frozen_string_literal: true

RSpec::Matchers.define :add_notification do |user, notification_type|
  match(notify_expectation_failures: true) do |actual|
    notifications = user.notifications
    before = notifications.count

    actual.call

    expect(notifications.count).to eq(before + 1), "expected 1 new notification, got #{notifications.count - before}"

    last_notification_type = notifications.last.notification_type
    expect(last_notification_type).to eq(Notification.types[notification_type]),
                                      "expected notification type to be '#{notification_type}', got '#{Notification.types.key(last_notification_type)}'"
  end

  match_when_negated do |actual|
    expect { actual.call }.to_not change { user.notifications.where(notification_type: Notification.types[notification_type]).count }
  end

  supports_block_expectations
end

RSpec::Matchers.define_negated_matcher :not_add_notification, :add_notification

RSpec.describe PostAlerter do
  fab!(:category) { Fabricate(:category) }

  fab!(:topic) { Fabricate(:topic) }
  fab!(:post) { Fabricate(:post) }

  fab!(:private_message_topic) { Fabricate(:private_message_topic) }
  fab!(:private_message_topic_post1) { Fabricate(:post, topic: private_message_topic) }
  fab!(:private_message_topic_post2) { Fabricate(:post, topic: private_message_topic) }

  fab!(:group) { Fabricate(:group) }

  fab!(:admin) { Fabricate(:admin) }
  fab!(:evil_trout) { Fabricate(:evil_trout) }
  fab!(:coding_horror) { Fabricate(:coding_horror) }
  fab!(:walterwhite) { Fabricate(:walter_white) }
  fab!(:user) { Fabricate(:user) }
  fab!(:tl2_user) { Fabricate(:user, trust_level: TrustLevel[2]) }

  def create_post_with_alerts(args = {})
    post = Fabricate(:post, args)
    PostAlerter.post_created(post)
  end

  context "with private message" do
    it "notifies for pms correctly" do
      pm = Fabricate(:topic, archetype: 'private_message', category_id: nil)
      op = Fabricate(:post, user: pm.user)
      pm.allowed_users << pm.user
      PostAlerter.post_created(op)

      reply = Fabricate(:post, user: pm.user, topic: pm, reply_to_post_number: 1)
      PostAlerter.post_created(reply)

      reply2 = Fabricate(:post, topic: pm, reply_to_post_number: 1)
      PostAlerter.post_created(reply2)

      # we get a green notification for a reply
      expect(Notification.where(user_id: pm.user_id).pluck_first(:notification_type)).to eq(Notification.types[:private_message])

      TopicUser.change(pm.user_id, pm.id, notification_level: TopicUser.notification_levels[:tracking])

      Notification.destroy_all

      reply3 = Fabricate(:post, topic: pm)
      PostAlerter.post_created(reply3)

      # no notification cause we are tracking
      expect(Notification.where(user_id: pm.user_id).count).to eq(0)

      Notification.destroy_all

      reply4 = Fabricate(:post, topic: pm, reply_to_post_number: 1)
      PostAlerter.post_created(reply4)

      # yes notification cause we were replied to
      expect(Notification.where(user_id: pm.user_id).count).to eq(1)

    end

    it "notifies about private message even if direct mention" do
      pm = Fabricate(:topic, archetype: 'private_message', category_id: nil)
      op = Fabricate(:post, topic: pm, user: pm.user, raw: "Hello @#{user.username}, nice to meet you")
      pm.allowed_users << pm.user
      pm.allowed_users << user
      TopicUser.create!(user_id: user.id, topic_id: pm.id, notification_level: TopicUser.notification_levels[:watching])
      PostAlerter.post_created(op)

      expect(Notification.where(user_id: user.id).pluck_first(:notification_type)).to eq(Notification.types[:private_message])
    end

    context "with group inboxes" do
      fab!(:user1) { Fabricate(:user) }
      fab!(:user2) { Fabricate(:user) }
      fab!(:group) { Fabricate(:group, users: [user2], name: "TestGroup", default_notification_level: 2) }
      fab!(:pm) { Fabricate(:topic, archetype: 'private_message', category_id: nil, allowed_groups: [group]) }
      fab!(:op) { Fabricate(:post, user: pm.user, topic: pm) }

      it "triggers :before_create_notifications_for_users" do
        pm.allowed_users << user1
        events = DiscourseEvent.track_events do
          PostAlerter.post_created(op)
        end

        expect(events).to include(event_name: :before_create_notifications_for_users, params: [[user1], op])
        expect(events).to include(event_name: :before_create_notifications_for_users, params: [[user2], op])

      end

      it "triggers group summary notification" do
        Jobs.run_immediately!
        TopicUser.change(user2.id, pm.id, notification_level: TopicUser.notification_levels[:tracking])

        PostAlerter.post_created(op)
        group_summary_notification = Notification.where(user_id: user2.id)

        expect(group_summary_notification.count).to eq(1)
        expect(group_summary_notification.first.notification_type).to eq(Notification.types[:group_message_summary])

        notification_payload = JSON.parse(group_summary_notification.first.data)
        expect(notification_payload["group_name"]).to eq(group.name)
        expect(notification_payload["inbox_count"]).to eq(1)

        # archiving the only PM clears the group summary notification
        GroupArchivedMessage.archive!(group.id, pm)
        expect(Notification.where(user_id: user2.id)).to be_blank

        # moving to inbox the only PM restores the group summary notification
        GroupArchivedMessage.move_to_inbox!(group.id, pm)
        group_summary_notification = Notification.where(user_id: user2.id)
        expect(group_summary_notification.first.notification_type).to eq(Notification.types[:group_message_summary])

        updated_payload = JSON.parse(group_summary_notification.first.data)
        expect(updated_payload["group_name"]).to eq(group.name)
        expect(updated_payload["inbox_count"]).to eq(1)

        # adding a second PM updates the count
        pm2 = Fabricate(:topic, archetype: 'private_message', category_id: nil, allowed_groups: [group])
        op2 = Fabricate(:post, user: pm2.user, topic: pm2)
        TopicUser.change(user2.id, pm2.id, notification_level: TopicUser.notification_levels[:tracking])

        PostAlerter.post_created(op2)
        group_summary_notification = Notification.where(user_id: user2.id)
        updated_payload = JSON.parse(group_summary_notification.first.data)

        expect(updated_payload["group_name"]).to eq(group.name)
        expect(updated_payload["inbox_count"]).to eq(2)

        # archiving the second PM quietly updates the group summary count for the acting user
        GroupArchivedMessage.archive!(group.id, pm2, acting_user_id: user2.id)
        group_summary_notification = Notification.where(user_id: user2.id)
        expect(group_summary_notification.first.read).to eq(true)
        updated_payload = JSON.parse(group_summary_notification.first.data)

        expect(updated_payload["inbox_count"]).to eq(1)

        # moving to inbox the second PM quietly updates the group summary count for the acting user
        GroupArchivedMessage.move_to_inbox!(group.id, pm2, acting_user_id: user2.id)
        group_summary_notification = Notification.where(user_id: user2.id)
        expect(group_summary_notification.first.read).to eq(true)
        updated_payload = JSON.parse(group_summary_notification.first.data)

        expect(updated_payload["group_name"]).to eq(group.name)
        expect(updated_payload["inbox_count"]).to eq(2)
      end

      it 'updates the consolidated group summary inbox count and bumps the notification' do
        user2.update!(last_seen_at: 5.minutes.ago)
        TopicUser.change(user2.id, pm.id, notification_level: TopicUser.notification_levels[:tracking])
        PostAlerter.post_created(op)

        starting_count = Notification.where(
          user_id: user2.id,
          notification_type: Notification.types[:group_message_summary]
        ).pluck("data::json ->> 'inbox_count'").last.to_i

        another_pm = Fabricate(:topic, archetype: 'private_message', category_id: nil, allowed_groups: [group])
        another_post = Fabricate(:post, user: another_pm.user, topic: another_pm)
        TopicUser.change(user2.id, another_pm.id, notification_level: TopicUser.notification_levels[:tracking])

        message_data = MessageBus.track_publish("/notification/#{user2.id}") do
          PostAlerter.post_created(another_post)
        end.first.data

        expect(Notification.where(user: user2).count).to eq(1)
        expect(message_data.dig(:last_notification, :notification, :data, :inbox_count)).to eq(starting_count + 1)
        expect(message_data[:unread_notifications]).to eq(1)
      end

      it 'sends a PM notification when replying to a member tracking the topic' do
        group.add(user1)

        post = Fabricate(:post, topic: pm, user: user1)
        TopicUser.change(user1.id, pm.id, notification_level: TopicUser.notification_levels[:tracking])

        expect {
          create_post_with_alerts(
            raw: 'this is a reply to your post...', topic: pm, user: user2,
            reply_to_post_number: post.post_number
          )
        }.to change(
          user1.notifications.where(notification_type: Notification.types[:private_message]),
          :count
        ).by(1)
      end

      it 'notifies a group member if someone replies to their post' do
        group.add(user1)

        post = Fabricate(:post, topic: pm, user: user1)
        TopicUser.change(user1.id, pm.id, notification_level: TopicUser.notification_levels[:regular])

        expect {
          create_post_with_alerts(
            raw: 'this is a reply to your post...', topic: pm, user: user2,
            reply_to_post_number: post.post_number
          )
        }.to change(user1.notifications, :count).by(1)
      end

      it 'notifies a group member if someone quotes their post' do
        group.add(user1)

        post = Fabricate(:post, topic: pm, user: user1)
        TopicUser.change(user1.id, pm.id, notification_level: TopicUser.notification_levels[:regular])
        quote_raw = <<~MD
          [quote="#{user1.username}, post:1, topic:#{pm.id}"]#{post.raw}[/quote]
        MD

        expect {
          create_post_with_alerts(
            raw: quote_raw, topic: pm, user: user2,
          )
        }.to change(user1.notifications, :count).by(1)
      end

      it "Doesn't notify non-admin users when their post is quoted inside a whisper" do
        group.add(admin)

        TopicUser.change(user2.id, pm.id, notification_level: TopicUser.notification_levels[:regular])
        quote_raw = <<~MD
          [quote="#{user2.username}, post:1, topic:#{pm.id}"]#{op.raw}[/quote]
        MD

        expect {
          create_post_with_alerts(
            raw: quote_raw, topic: pm, user: admin, post_type: Post.types[:whisper]
          )
        }.not_to change(user2.notifications, :count)
      end
    end
  end

  context "with unread" do
    it "does not return whispers as unread posts" do
      _whisper = Fabricate(:post, raw: 'this is a whisper post',
                                  user: admin,
                                  topic: post.topic,
                                  reply_to_post_number: post.post_number,
                                  post_type: Post.types[:whisper])

      expect(PostAlerter.new.first_unread_post(post.user, post.topic)).to be_blank
    end
  end

  context 'with edits' do
    it 'notifies correctly on edits' do
      Jobs.run_immediately!
      PostActionNotifier.enable

      post = Fabricate(:post, raw: 'I love waffles')

      expect do
        post.revise(admin, raw: 'I made a revision')
      end.to add_notification(post.user, :edited)

      # lets also like this post which should trigger a notification
      expect do
        PostActionCreator.new(
          admin,
          post,
          PostActionType.types[:like]
        ).perform
      end.to add_notification(post.user, :liked)

      # skip this notification cause we already notified on an edit by the same user
      # in the previous edit
      freeze_time 2.hours.from_now

      expect do
        post.revise(admin, raw: 'I made another revision')
      end.to_not change { Notification.count }

      # this we do not skip cause 1 day has passed
      freeze_time 23.hours.from_now

      expect do
        post.revise(admin, raw: 'I made another revision xyz')
      end.to add_notification(post.user, :edited)

      expect do
        post.revise(Fabricate(:admin), raw: 'I made a revision')
      end.to add_notification(post.user, :edited)

      freeze_time 2.hours.from_now

      expect do
        post.revise(admin, raw: 'I made another revision')
      end.to add_notification(post.user, :edited)
    end

    it 'notifies flaggers when flagged post gets unhidden by edit' do
      post = create_post

      PostActionNotifier.enable
      Reviewable.set_priorities(high: 4.0)
      SiteSetting.hide_post_sensitivity = Reviewable.sensitivities[:low]

      PostActionCreator.spam(evil_trout, post)
      PostActionCreator.spam(walterwhite, post)

      post.reload
      expect(post.hidden).to eq(true)

      expect {
        post.revise(post.user, raw: post.raw + " ha I edited it ")
      }.to add_notification(evil_trout, :edited)
        .and add_notification(walterwhite, :edited)

      post.reload
      expect(post.hidden).to eq(false)

      notification = walterwhite.notifications.last
      expect(notification.topic_id).to eq(post.topic.id)
      expect(notification.post_number).to eq(post.post_number)
      expect(notification.data_hash["display_username"]).to eq(post.user.username)

      PostActionCreator.create(coding_horror, post, :spam)
      PostActionCreator.create(walterwhite, post, :off_topic)

      post.reload
      expect(post.hidden).to eq(true)

      expect {
        post.revise(post.user, raw: post.raw + " ha I edited it again ")
      }.to not_add_notification(evil_trout, :edited)
        .and not_add_notification(coding_horror, :edited)
        .and not_add_notification(walterwhite, :edited)
    end
  end

  context 'with quotes' do
    fab!(:category) { Fabricate(:category) }
    fab!(:topic) { Fabricate(:topic, category: category) }

    it 'does not notify for muted users' do
      post = Fabricate(:post, raw: '[quote="Eviltrout, post:1"]whatup[/quote]', topic: topic)
      MutedUser.create!(user_id: evil_trout.id, muted_user_id: post.user_id)

      expect {
        PostAlerter.post_created(post)
      }.not_to change(evil_trout.notifications, :count)
    end

    it 'does not notify for ignored users' do
      post = Fabricate(:post, raw: '[quote="EvilTrout, post:1"]whatup[/quote]', topic: topic)
      Fabricate(:ignored_user, user: evil_trout, ignored_user: post.user)

      expect {
        PostAlerter.post_created(post)
      }.not_to change(evil_trout.notifications, :count)
    end

    it 'does not notify for users with new reply notification' do
      post = Fabricate(:post, raw: '[quote="eviltRout, post:1"]whatup[/quote]', topic: topic)
      notification = Notification.create!(topic: post.topic,
                                          post_number: post.post_number,
                                          read: false,
                                          notification_type: Notification.types[:replied],
                                          user: evil_trout,
                                          data: { topic_title: "test topic" }.to_json
                                         )
      expect {
        PostAlerter.post_edited(post)
      }.not_to change(evil_trout.notifications, :count)

      notification.destroy
      expect {
        PostAlerter.post_edited(post)
      }.to change(evil_trout.notifications, :count).by(1)
    end

    it 'does not collapse quote notifications' do
      expect {
        2.times do
          create_post_with_alerts(
            raw: '[quote="eviltrout, post:1"]whatup[/quote]',
            topic: topic
          )
        end
      }.to change(evil_trout.notifications, :count).by(2)
    end

    it "won't notify the user a second time on revision" do
      p1 = create_post_with_alerts(raw: '[quote="Evil Trout, post:1"]whatup[/quote]')
      expect {
        p1.revise(p1.user, raw: '[quote="Evil Trout, post:1"]whatup now?[/quote]')
      }.not_to change(evil_trout.notifications, :count)
    end

    it "doesn't notify the poster" do
      topic = create_post_with_alerts.topic
      expect {
        Fabricate(:post, topic: topic, user: topic.user, raw: '[quote="Bruce Wayne, post:1"]whatup[/quote]')
      }.not_to change(topic.user.notifications, :count)
    end

    it "triggers :before_create_notifications_for_users" do
      post = Fabricate(:post, raw: '[quote="eviltrout, post:1"]whatup[/quote]')
      events = DiscourseEvent.track_events do
        PostAlerter.post_created(post)
      end
      expect(events).to include(event_name: :before_create_notifications_for_users, params: [[evil_trout], post])
    end

    context "with notifications when prioritizing full names" do
      before do
        SiteSetting.prioritize_username_in_ux = false
        SiteSetting.display_name_on_posts = true
      end

      it 'sends to correct user' do
        quote = <<~MD
          [quote="#{evil_trout.name}, post:1, username:#{evil_trout.username}"]whatup[/quote]
        MD

        expect {
          create_post_with_alerts(
            raw: quote,
            topic: topic
          )
        }.to change(evil_trout.notifications, :count).by(1)
      end

      it 'sends to correct users when nested quotes with multiple users' do
        quote = <<~MD
          [quote="#{evil_trout.name}, post:1, username:#{evil_trout.username}"]this [quote="#{walterwhite.name}, post:2, username:#{walterwhite.username}"]whatup[/quote][/quote]
        MD

        expect {
          create_post_with_alerts(
            raw: quote,
            topic: topic
          )
        }.to change(evil_trout.notifications, :count).by(1)
          .and change(walterwhite.notifications, :count).by(1)
      end

      it 'sends to correct users when multiple quotes' do
        user = Fabricate(:user)
        quote = <<~MD
          [quote="#{evil_trout.name}, post:1, username:#{evil_trout.username}"]"username:#{user.username}" [/quote]/n [quote="#{walterwhite.name}, post:2, username:#{walterwhite.username}"]whatup[/quote]
        MD

        expect {
          create_post_with_alerts(
            raw: quote,
            topic: topic
          )
        }.to change(evil_trout.notifications, :count).by(1)
          .and change(walterwhite.notifications, :count).by(1)
          .and not_change(user.notifications, :count)
      end

      it "sends to correct user when user has a full name that matches another user's username" do
        user_with_matching_full_name = Fabricate(:user, name: evil_trout.username)
        quote = <<~MD
          [quote="#{user_with_matching_full_name.name}, post:1, username:#{user_with_matching_full_name.username}"]this [/quote]
        MD

        expect {
          create_post_with_alerts(
            raw: quote,
            topic: topic
          )
        }.to change(user_with_matching_full_name.notifications, :count).by(1)
          .and not_change(evil_trout.notifications, :count)
      end
    end
  end

  context 'with linked' do
    let(:post1) { create_post }
    let(:user) { post1.user }
    let(:linking_post) { create_post(raw: "my magic topic\n##{Discourse.base_url}#{post1.url}") }

    before do
      Jobs.run_immediately!
    end

    it "will notify correctly on linking" do
      linking_post

      expect(user.notifications.count).to eq(1)

      watcher = Fabricate(:user)
      TopicUser.create!(user_id: watcher.id, topic_id: topic.id, notification_level: TopicUser.notification_levels[:watching])

      create_post(topic_id: topic.id, user: user, raw: "my magic topic\n##{Discourse.base_url}#{post1.url}")

      user.reload
      expect(user.notifications.where(notification_type: Notification.types[:linked]).count).to eq(1)

      expect(watcher.notifications.count).to eq(1)

      # don't notify on reflection
      post1.reload
      expect(PostAlerter.new.extract_linked_users(post1).length).to eq(0)
    end

    it "triggers :before_create_notifications_for_users" do
      events = DiscourseEvent.track_events do
        linking_post
      end
      expect(events).to include(event_name: :before_create_notifications_for_users, params: [[user], linking_post])
    end

    it "doesn't notify the linked user if the user is staged and the category is restricted and allows strangers" do
      staged_user = Fabricate(:staged)
      group_member = Fabricate(:user)
      group.add(group_member)

      private_category = Fabricate(
        :private_category, group: group,
                           email_in: 'test@test.com', email_in_allow_strangers: true
      )

      staged_user_post = create_post(user: staged_user, category: private_category)

      linking = create_post(
        user: group_member,
        category: private_category,
        raw: "my magic topic\n##{Discourse.base_url}#{staged_user_post.url}")

      staged_user.reload
      expect(staged_user.notifications.where(notification_type: Notification.types[:linked]).count).to eq(0)
    end
  end

  context 'with @here' do
    let(:post) { create_post_with_alerts(raw: "Hello @here how are you?", user: tl2_user, topic: topic) }
    fab!(:other_post) { Fabricate(:post, topic: topic) }

    before do
      Jobs.run_immediately!
    end

    it 'does not notify unrelated users' do
      expect { post }.not_to change(evil_trout.notifications, :count)
    end

    it 'does not work if user here exists' do
      Fabricate(:user, username: SiteSetting.here_mention)
      expect { post }.not_to change(other_post.user.notifications, :count)
    end

    it 'notifies users who replied' do
      post2 = Fabricate(:post, topic: topic, post_type: Post.types[:whisper])
      post3 = Fabricate(:post, topic: topic)

      expect { post }
        .to change(other_post.user.notifications, :count).by(1)
        .and not_change(post2.user.notifications, :count)
        .and change(post3.user.notifications, :count).by(1)
    end

    it 'notifies users who whispered' do
      post2 = Fabricate(:post, topic: topic, post_type: Post.types[:whisper])
      post3 = Fabricate(:post, topic: topic)

      tl2_user.grant_admin!

      expect { post }
        .to change(other_post.user.notifications, :count).by(1)
        .and change(post2.user.notifications, :count).by(1)
        .and change(post3.user.notifications, :count).by(1)
    end

    it 'notifies only last max_here_mentioned users' do
      SiteSetting.max_here_mentioned = 2
      3.times { Fabricate(:post, topic: topic) }
      expect { post }.to change { Notification.count }.by(2)
    end
  end

  context 'with @group mentions' do

    fab!(:group) { Fabricate(:group, name: 'group', mentionable_level: Group::ALIAS_LEVELS[:everyone]) }
    let(:post) { create_post_with_alerts(raw: "Hello @group how are you?") }
    before { group.add(evil_trout) }

    it 'notifies users correctly' do
      expect {
        post
      }.to change(evil_trout.notifications, :count).by(1)

      expect(GroupMention.count).to eq(1)

      Fabricate(:group, name: 'group-alt', mentionable_level: Group::ALIAS_LEVELS[:everyone])

      expect {
        create_post_with_alerts(raw: "Hello, @group-alt should not trigger a notification?")
      }.not_to change(evil_trout.notifications, :count)

      expect(GroupMention.count).to eq(2)

      group.update_columns(mentionable_level: Group::ALIAS_LEVELS[:members_mods_and_admins])
      expect {
        create_post_with_alerts(raw: "Hello @group you are not mentionable")
      }.not_to change(evil_trout.notifications, :count)

      expect(GroupMention.count).to eq(3)

      group.update_columns(mentionable_level: Group::ALIAS_LEVELS[:owners_mods_and_admins])
      group.add_owner(user)
      expect {
        create_post_with_alerts(raw: "Hello @group the owner can mention you", user: user)
      }.to change(evil_trout.notifications, :count).by(1)

      expect(GroupMention.count).to eq(4)
    end

    it 'takes private mention as precedence' do
      expect {
        create_post_with_alerts(raw: "Hello @group and @eviltrout, nice to meet you")
      }.to change(evil_trout.notifications, :count).by(1)
      expect(evil_trout.notifications.last.notification_type).to eq(Notification.types[:mentioned])
    end

    it "triggers :before_create_notifications_for_users" do
      events = DiscourseEvent.track_events do
        post
      end
      expect(events).to include(event_name: :before_create_notifications_for_users, params: [[evil_trout], post])
    end
  end

  context 'with @mentions' do

    let(:mention_post) { create_post_with_alerts(user: user, raw: 'Hello @eviltrout') }
    let(:topic) { mention_post.topic }

    before do
      Jobs.run_immediately!
    end

    it 'notifies a user' do
      expect {
        mention_post
      }.to change(evil_trout.notifications, :count).by(1)
    end

    it "won't notify the user a second time on revision" do
      mention_post
      expect {
        mention_post.revise(mention_post.user, raw: "New raw content that still mentions @eviltrout")
      }.not_to change(evil_trout.notifications, :count)
    end

    it "doesn't notify the user who created the topic in regular mode" do
      topic.notify_regular!(user)
      mention_post
      expect {
        create_post_with_alerts(user: user, raw: 'second post', topic: topic)
      }.not_to change(user.notifications, :count)
    end

    it "triggers :before_create_notifications_for_users" do
      events = DiscourseEvent.track_events do
        mention_post
      end
      expect(events).to include(event_name: :before_create_notifications_for_users, params: [[evil_trout], mention_post])
    end

    it "notification comes from editor if mention is added later" do
      post = create_post_with_alerts(user: user, raw: 'No mention here.')
      expect {
        post.revise(admin, raw: "Mention @eviltrout in this edit.")
      }.to change(evil_trout.notifications, :count)
      n = evil_trout.notifications.last
      expect(n.data_hash["original_username"]).to eq(admin.username)
    end

    it "doesn't notify the last post editor if they mention themselves" do
      post = create_post_with_alerts(user: user, raw: 'Post without a mention.')
      expect {
        post.revise(evil_trout, raw: "O hai, @eviltrout!")
      }.not_to change(evil_trout.notifications, :count)
    end

    fab!(:alice) { Fabricate(:user, username: 'alice') }
    fab!(:bob) { Fabricate(:user, username: 'bob') }
    fab!(:carol) { Fabricate(:admin, username: 'carol') }
    fab!(:dave) { Fabricate(:user, username: 'dave') }
    fab!(:eve) { Fabricate(:user, username: 'eve') }
    fab!(:group) { Fabricate(:group, name: 'group', mentionable_level: Group::ALIAS_LEVELS[:everyone]) }

    before do
      group.bulk_add([alice.id, eve.id])
    end

    def create_post_with_alerts(args = {})
      post = Fabricate(:post, args)
      PostAlerter.post_created(post)
    end

    def set_topic_notification_level(user, topic, level_name)
      TopicUser.change(user.id, topic.id, notification_level: TopicUser.notification_levels[level_name])
    end

    context "with topic" do
      fab!(:topic) { Fabricate(:topic, user: alice) }

      [:watching, :tracking, :regular].each do |notification_level|
        context "when notification level is '#{notification_level}'" do
          before do
            set_topic_notification_level(alice, topic, notification_level)
          end

          it "notifies about @username mention" do
            args = { user: bob, topic: topic, raw: 'Hello @alice' }
            expect { create_post_with_alerts(args) }.to add_notification(alice, :mentioned)
          end
        end
      end

      context "when notification level is 'muted'" do
        before do
          set_topic_notification_level(alice, topic, :muted)
        end

        it "does not notify about @username mention" do
          args = { user: bob, topic: topic, raw: 'Hello @alice' }
          expect { create_post_with_alerts(args) }.to_not add_notification(alice, :mentioned)
        end
      end
    end

    context "with message to users" do
      fab!(:pm_topic) do
        Fabricate(:private_message_topic,
                  user: alice,
                  topic_allowed_users: [
                    Fabricate.build(:topic_allowed_user, user: alice),
                    Fabricate.build(:topic_allowed_user, user: bob),
                    Fabricate.build(:topic_allowed_user, user: Discourse.system_user)
                  ]
        )
      end

      context "when user is part of conversation" do
        [:watching, :tracking, :regular].each do |notification_level|
          context "when notification level is '#{notification_level}'" do
            before do
              set_topic_notification_level(alice, pm_topic, notification_level)
            end
            let(:expected_notification) {
              notification_level == :watching ? :private_message : :mentioned
            }

            it "notifies about @username mention" do
              args = { user: bob, topic: pm_topic, raw: 'Hello @alice' }
              expect { create_post_with_alerts(args) }.to add_notification(alice, expected_notification)
            end

            it "notifies about @username mentions by non-human users" do
              args = { user: Discourse.system_user, topic: pm_topic, raw: 'Hello @alice' }
              expect { create_post_with_alerts(args) }.to add_notification(alice, expected_notification)
            end

            it "notifies about @group mention when allowed user is part of group" do
              args = { user: bob, topic: pm_topic, raw: 'Hello @group' }
              expect { create_post_with_alerts(args) }.to add_notification(alice, :group_mentioned)
            end
          end
        end

        context "when notification level is 'muted'" do
          before do
            set_topic_notification_level(alice, pm_topic, :muted)
          end

          it "does not notify about @username mention" do
            args = { user: bob, topic: pm_topic, raw: 'Hello @alice' }
            expect { create_post_with_alerts(args) }.to_not add_notification(alice, :mentioned)
          end
        end
      end

      context "when user is not part of conversation" do
        it "does not notify about @username mention even though mentioned user is an admin" do
          args = { user: bob, topic: pm_topic, raw: 'Hello @carol' }
          expect { create_post_with_alerts(args) }.to_not add_notification(carol, :mentioned)
        end

        it "does not notify about @username mention by non-human user even though mentioned user is an admin" do
          args = { user: Discourse.system_user, topic: pm_topic, raw: 'Hello @carol' }
          expect { create_post_with_alerts(args) }.to_not add_notification(carol, :mentioned)
        end

        it "does not notify about @username mention when mentioned user is not allowed to see message" do
          args = { user: bob, topic: pm_topic, raw: 'Hello @dave' }
          expect { create_post_with_alerts(args) }.to_not add_notification(dave, :mentioned)
        end

        it "does not notify about @group mention when user is not an allowed user" do
          args = { user: bob, topic: pm_topic, raw: 'Hello @group' }
          expect { create_post_with_alerts(args) }.to_not add_notification(eve, :group_mentioned)
        end
      end
    end

    context "with message to group" do
      fab!(:some_group) { Fabricate(:group, name: 'some_group', mentionable_level: Group::ALIAS_LEVELS[:everyone]) }
      fab!(:pm_topic) do
        Fabricate(:private_message_topic,
                  user: alice,
                  topic_allowed_groups: [
                    Fabricate.build(:topic_allowed_group, group: group)
                  ],
                  topic_allowed_users: [
                    Fabricate.build(:topic_allowed_user, user: Discourse.system_user)
                  ]
        )
      end

      before do
        some_group.bulk_add([alice.id, carol.id])
      end

      context "when group is part of conversation" do
        [:watching, :tracking, :regular].each do |notification_level|
          context "when notification level is '#{notification_level}'" do
            before do
              set_topic_notification_level(alice, pm_topic, notification_level)
            end

            it "notifies about @group mention" do
              args = { user: bob, topic: pm_topic, raw: 'Hello @group' }
              expect { create_post_with_alerts(args) }.to add_notification(alice, :group_mentioned)
            end

            it "notifies about @group mentions by non-human users" do
              args = { user: Discourse.system_user, topic: pm_topic, raw: 'Hello @group' }
              expect { create_post_with_alerts(args) }.to add_notification(alice, :group_mentioned)
            end

            it "notifies about @username mention when user belongs to allowed group" do
              args = { user: bob, topic: pm_topic, raw: 'Hello @alice' }
              expect { create_post_with_alerts(args) }.to add_notification(alice, :mentioned)
            end
          end
        end

        context "when notification level is 'muted'" do
          before do
            set_topic_notification_level(alice, pm_topic, :muted)
          end

          it "does not notify about @group mention" do
            args = { user: bob, topic: pm_topic, raw: 'Hello @group' }
            expect { create_post_with_alerts(args) }.to_not add_notification(alice, :group_mentioned)
          end
        end
      end

      context "when group is not part of conversation" do
        it "does not notify about @group mention even though mentioned user is an admin" do
          args = { user: bob, topic: pm_topic, raw: 'Hello @some_group' }
          expect { create_post_with_alerts(args) }.to_not add_notification(carol, :group_mentioned)
        end

        it "does not notify about @group mention by non-human user even though mentioned user is an admin" do
          args = { user: Discourse.system_user, topic: pm_topic, raw: 'Hello @some_group' }
          expect { create_post_with_alerts(args) }.to_not add_notification(carol, :group_mentioned)
        end

        it "does not notify about @username mention when user doesn't belong to allowed group" do
          args = { user: bob, topic: pm_topic, raw: 'Hello @dave' }
          expect { create_post_with_alerts(args) }.to_not add_notification(dave, :mentioned)
        end
      end
    end
  end

  describe ".create_notification" do
    fab!(:topic) { Fabricate(:private_message_topic, user: user, created_at: 1.hour.ago) }
    fab!(:post) { Fabricate(:post, topic: topic, created_at: 1.hour.ago) }
    let(:type) { Notification.types[:private_message] }

    it "creates a notification for PMs" do
      post.revise(user, { raw: 'This is the revised post' }, revised_at: Time.zone.now)

      expect {
        PostAlerter.new.create_notification(user, type, post)
      }.to change { user.notifications.count }.by(1)

      expect(user.notifications.last.data_hash["topic_title"]).to eq(topic.title)
    end

    it "keeps the original title for PMs" do
      original_title = topic.title

      post.revise(user, { title: "This is the revised title" }, revised_at: Time.now)

      expect {
        PostAlerter.new.create_notification(user, type, post)
      }.to change { user.notifications.count }.by(1)

      expect(user.notifications.last.data_hash["topic_title"]).to eq(original_title)
    end

    it "triggers :pre_notification_alert" do
      events = DiscourseEvent.track_events do
        PostAlerter.new.create_notification(user, type, post)
      end

      payload = {
       notification_type: type,
       post_number: post.post_number,
       topic_title: post.topic.title,
       topic_id: post.topic.id,
       excerpt: post.excerpt(400, text_entities: true, strip_links: true, remap_emoji: true),
       username: post.username,
       post_url: post.url
      }

      expect(events).to include(event_name: :pre_notification_alert, params: [user, payload])
    end

    it "does not alert when revising and changing notification type" do
      PostAlerter.new.create_notification(user, type, post)

      post.revise(user, { raw: "Editing post to fake include a mention of @eviltrout" }, revised_at: Time.now)

      events = DiscourseEvent.track_events do
        PostAlerter.new.create_notification(user, Notification.types[:mentioned], post)
      end

      payload = {
       notification_type: type,
       post_number: post.post_number,
       topic_title: post.topic.title,
       topic_id: post.topic.id,
       excerpt: post.excerpt(400, text_entities: true, strip_links: true, remap_emoji: true),
       username: post.username,
       post_url: post.url
      }

      expect(events).not_to include(event_name: :pre_notification_alert, params: [user, payload])
    end

    it "triggers :before_create_notification" do
      type = Notification.types[:private_message]
      events = DiscourseEvent.track_events do
        PostAlerter.new.create_notification(user, type, post, {})
      end
      expect(events).to include(event_name: :before_create_notification, params: [user, type, post, {}])
    end
  end

  describe ".push_notification" do
    let(:mention_post) { create_post_with_alerts(user: user, raw: 'Hello @eviltrout :heart:') }
    let(:topic) { mention_post.topic }

    before do
      SiteSetting.allowed_user_api_push_urls = "https://site.com/push|https://site2.com/push"
      2.times do |i|
        UserApiKey.create!(user_id: evil_trout.id,
                           client_id: "xxx#{i}",
                           application_name: "iPhone#{i}",
                           scopes: ['notifications'].map { |name| UserApiKeyScope.new(name: name) },
                           push_url: "https://site2.com/push")
      end
    end

    describe "DiscoursePluginRegistry#push_notification_filters" do
      it "sends push notifications when all filters pass" do
        Plugin::Instance.new.register_push_notification_filter do |user, payload|
          true
        end

        expect { mention_post }.to change { Jobs::PushNotification.jobs.count }.by(1)
        DiscoursePluginRegistry.reset!
      end

      it "does not send push notifications when a filters returns false" do
        Plugin::Instance.new.register_push_notification_filter do |user, payload|
          false
        end
        expect { mention_post }.not_to change { Jobs::PushNotification.jobs.count }
        DiscoursePluginRegistry.reset!
      end
    end

    it "pushes nothing to suspended users" do
      evil_trout.update_columns(suspended_till: 1.year.from_now)
      expect { mention_post }.to_not change { Jobs::PushNotification.jobs.count }
    end

    it "pushes nothing when the user is in 'do not disturb'" do
      Fabricate(:do_not_disturb_timing, user: evil_trout, starts_at: Time.zone.now, ends_at: 1.day.from_now)

      expect { mention_post }.to_not change { Jobs::PushNotification.jobs.count }
    end

    it "correctly pushes notifications if configured correctly" do
      Jobs.run_immediately!
      body = nil
      headers = nil

      stub_request(:post, "https://site2.com/push")
        .to_return do |request|
          body = request.body
          headers = request.headers
          { status: 200, body: "OK" }
        end

      set_subfolder "/subpath"
      payload = {
        "secret_key" => SiteSetting.push_api_secret_key,
        "url" => Discourse.base_url,
        "title" => SiteSetting.title,
        "description" => SiteSetting.site_description,
        "notifications" => [
        {
          'notification_type' => 1,
          'post_number' => 1,
          'topic_title' => topic.title,
          'topic_id' => topic.id,
          'excerpt' => 'Hello @eviltrout ❤',
          'username' => user.username,
          'url' => UrlHelper.absolute(Discourse.base_path + mention_post.url),
          'client_id' => 'xxx0'
        },
        {
          'notification_type' => 1,
          'post_number' => 1,
          'topic_title' => topic.title,
          'topic_id' => topic.id,
          'excerpt' => 'Hello @eviltrout ❤',
          'username' => user.username,
          'url' => UrlHelper.absolute(Discourse.base_path + mention_post.url),
          'client_id' => 'xxx1'
        }
        ]
      }

      post = mention_post

      expect(JSON.parse(body)).to eq(payload)
      expect(headers["Content-Type"]).to eq('application/json')

      TopicUser.change(evil_trout.id, topic.id, notification_level: TopicUser.notification_levels[:watching])

      post = Fabricate(:post, topic: post.topic, user_id: evil_trout.id)
      user2 = Fabricate(:user)

      # if we collapse a reply notification we should get notified on the correct post
      new_post = create_post_with_alerts(topic: post.topic, user_id: user.id, reply_to_post_number: post.post_number, raw: 'this is my first reply')

      changes = {
        "notification_type" => Notification.types[:posted],
        "post_number" => new_post.post_number,
        "username" => new_post.user.username,
        "excerpt" => new_post.raw,
        "url" => UrlHelper.absolute(Discourse.base_path + new_post.url)
      }

      payload["notifications"][0].merge! changes
      payload["notifications"][1].merge! changes

      expect(JSON.parse(body)).to eq(payload)

      new_post = create_post_with_alerts(topic: post.topic, user_id: user2.id, reply_to_post_number: post.post_number, raw: 'this is my second reply')

      changes = {
        "post_number" => new_post.post_number,
        "username" => new_post.user.username,
        "excerpt" => new_post.raw,
        "url" => UrlHelper.absolute(Discourse.base_path + new_post.url)
      }

      payload["notifications"][0].merge! changes
      payload["notifications"][1].merge! changes

      expect(JSON.parse(body)).to eq(payload)

    end
  end

  describe ".create_notification_alert" do
    it "does nothing for suspended users" do
      evil_trout.update_columns(suspended_till: 1.year.from_now)

      events = nil
      messages = MessageBus.track_publish do
        events = DiscourseEvent.track_events do
          PostAlerter.create_notification_alert(
            user: evil_trout,
            post: post,
            notification_type: Notification.types[:custom],
            excerpt: "excerpt",
            username: "username"
          )
        end
      end

      expect(events.size).to eq(0)
      expect(messages.size).to eq(0)
      expect(Jobs::PushNotification.jobs.size).to eq(0)
    end

    it "does not publish to MessageBus /notification-alert if the user has not been seen for > 30 days, but still sends a push notification" do
      evil_trout.update_columns(last_seen_at: 31.days.ago)

      SiteSetting.allowed_user_api_push_urls = "https://site2.com/push"
      UserApiKey.create!(user_id: evil_trout.id,
                         client_id: "xxx#1",
                         application_name: "iPhone1",
                         scopes: ['notifications'].map { |name| UserApiKeyScope.new(name: name) },
                         push_url: "https://site2.com/push")

      events = nil
      messages = MessageBus.track_publish do
        events = DiscourseEvent.track_events do
          PostAlerter.create_notification_alert(
            user: evil_trout,
            post: post,
            notification_type: Notification.types[:custom],
            excerpt: "excerpt",
            username: "username"
          )
        end
      end

      expect(events.size).to eq(2)
      expect(messages.size).to eq(0)
      expect(Jobs::PushNotification.jobs.size).to eq(1)
    end
  end

  describe "watching_first_post" do
    fab!(:user) { Fabricate(:user) }
    fab!(:category) { Fabricate(:category) }
    fab!(:tag)  { Fabricate(:tag) }
    fab!(:topic) { Fabricate(:topic, category: category, tags: [tag]) }
    fab!(:post) { Fabricate(:post, topic: topic) }

    it "doesn't notify people who aren't watching" do
      PostAlerter.post_created(post)
      expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(0)
    end

    it "notifies the user who is following the first post category" do
      level = CategoryUser.notification_levels[:watching_first_post]
      CategoryUser.set_notification_level_for_category(user, level, category.id)
      PostAlerter.new.after_save_post(post, true)
      expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(1)
    end

    it "doesn't notify when the record is not new" do
      level = CategoryUser.notification_levels[:watching_first_post]
      CategoryUser.set_notification_level_for_category(user, level, category.id)
      PostAlerter.new.after_save_post(post, false)
      expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(0)
    end

    it "notifies the user who is following the first post tag" do
      level = TagUser.notification_levels[:watching_first_post]
      TagUser.change(user.id, tag.id, level)
      PostAlerter.post_created(post)
      expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(1)
    end

    it "notifies the user who is following the first post group" do
      GroupUser.create(group_id: group.id, user_id: user.id)
      GroupUser.create(group_id: group.id, user_id: post.user.id)
      topic.topic_allowed_groups.create(group_id: group.id)

      level = GroupUser.notification_levels[:watching_first_post]
      GroupUser.where(user_id: user.id, group_id: group.id).update_all(notification_level: level)

      PostAlerter.post_created(post)
      expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(1)
    end

    it "triggers :before_create_notifications_for_users" do
      level = CategoryUser.notification_levels[:watching_first_post]
      CategoryUser.set_notification_level_for_category(user, level, category.id)
      events = DiscourseEvent.track_events do
        PostAlerter.new.after_save_post(post, true)
      end
      expect(events).to include(event_name: :before_create_notifications_for_users, params: [[user], post])
    end
  end

  context "with replies" do
    it "triggers :before_create_notifications_for_users" do
      _post = Fabricate(:post, user: user, topic: topic)
      reply = Fabricate(:post, topic: topic, reply_to_post_number: 1)
      events = DiscourseEvent.track_events do
        PostAlerter.post_created(reply)
      end
      expect(events).to include(event_name: :before_create_notifications_for_users, params: [[user], reply])
    end

    it "notifies about regular reply" do
      _post = Fabricate(:post, user: user, topic: topic)

      reply = Fabricate(:post, topic: topic, reply_to_post_number: 1)
      PostAlerter.post_created(reply)

      expect(user.notifications.where(notification_type: Notification.types[:replied]).count).to eq(1)
    end

    it "doesn't notify regular user about whispered reply" do
      _post = Fabricate(:post, user: user, topic: topic)

      whispered_reply = Fabricate(:post, user: admin, topic: topic, post_type: Post.types[:whisper], reply_to_post_number: 1)
      PostAlerter.post_created(whispered_reply)

      expect(user.notifications.where(notification_type: Notification.types[:replied]).count).to eq(0)
    end

    it "notifies staff user about whispered reply" do
      admin1 = Fabricate(:admin)
      admin2 = Fabricate(:admin)

      _post = Fabricate(:post, user: user, topic: topic)

      whispered_reply1 = Fabricate(:post, user: admin1, topic: topic, post_type: Post.types[:whisper], reply_to_post_number: 1)
      whispered_reply2 = Fabricate(:post, user: admin2, topic: topic, post_type: Post.types[:whisper], reply_to_post_number: 2)
      PostAlerter.post_created(whispered_reply1)
      PostAlerter.post_created(whispered_reply2)

      expect(admin1.notifications.where(notification_type: Notification.types[:replied]).count).to eq(1)

      TopicUser.change(admin1.id, topic.id, notification_level: TopicUser.notification_levels[:watching])

      # this should change nothing cause the moderator post has an action code
      # if we have an action code then we should never have notifications, this is rare but
      # assign whispers are like this
      whispered_reply3 = topic.add_moderator_post(admin2, "i am a reply", post_type: Post.types[:whisper], action_code: 'moderator_thing')
      PostAlerter.post_created(whispered_reply3)

      # if this whisper is not ignored like it should we would see a posted notification and no replied notifications
      notifications = admin1.notifications.where(topic_id: topic.id).to_a

      expect(notifications.first.notification_type).to eq(Notification.types[:replied])
      expect(notifications.length).to eq(1)
      expect(notifications.first.post_number).to eq(whispered_reply2.post_number)
    end

    it "sends email notifications only to users not on CC list of incoming email" do
      alice = Fabricate(:user, username: "alice", email: "alice@example.com")
      bob = Fabricate(:user, username: "bob", email: "bob@example.com")
      carol = Fabricate(:user, username: "carol", email: "carol@example.com", staged: true)
      dave = Fabricate(:user, username: "dave", email: "dave@example.com", staged: true)
      erin = Fabricate(:user, username: "erin", email: "erin@example.com")

      topic = Fabricate(:private_message_topic, topic_allowed_users: [
        Fabricate.build(:topic_allowed_user, user: alice),
        Fabricate.build(:topic_allowed_user, user: bob),
        Fabricate.build(:topic_allowed_user, user: carol),
        Fabricate.build(:topic_allowed_user, user: dave),
        Fabricate.build(:topic_allowed_user, user: erin)
      ])
      _post = Fabricate(:post, user: alice, topic: topic)

      TopicUser.change(alice.id, topic.id, notification_level: TopicUser.notification_levels[:watching])
      TopicUser.change(bob.id, topic.id, notification_level: TopicUser.notification_levels[:watching])
      TopicUser.change(erin.id, topic.id, notification_level: TopicUser.notification_levels[:watching])

      email = Fabricate(:incoming_email,
                        raw: <<~RAW,
                          Return-Path: <bob@example.com>
                          From: Bob <bob@example.com>
                          To: meta+1234@discoursemail.com, dave@example.com
                          CC: carol@example.com, erin@example.com
                          Subject: Hello world
                          Date: Fri, 15 Jan 2016 00:12:43 +0100
                          Message-ID: <12345@example.com>
                          Mime-Version: 1.0
                          Content-Type: text/plain; charset=UTF-8
                          Content-Transfer-Encoding: quoted-printable

                          This post was created by email.
                        RAW
                        from_address: "bob@example.com",
                        to_addresses: "meta+1234@discoursemail.com;dave@example.com",
                        cc_addresses: "carol@example.com;erin@example.com")
      reply = Fabricate(:post_via_email, user: bob, topic: topic, incoming_email: email, reply_to_post_number: 1)

      NotificationEmailer.expects(:process_notification).with { |n| n.user_id == alice.id }.once
      NotificationEmailer.expects(:process_notification).with { |n| n.user_id == bob.id }.never
      NotificationEmailer.expects(:process_notification).with { |n| n.user_id == carol.id }.never
      NotificationEmailer.expects(:process_notification).with { |n| n.user_id == dave.id }.never
      NotificationEmailer.expects(:process_notification).with { |n| n.user_id == erin.id }.never

      PostAlerter.post_created(reply)

      expect(alice.notifications.count).to eq(1)
      expect(bob.notifications.count).to eq(0)
      expect(carol.notifications.count).to eq(1)
      expect(dave.notifications.count).to eq(1)
      expect(erin.notifications.count).to eq(1)
    end

    it "does not send email notifications to staged users when notification originates in mailinglist mirror category" do
      category = Fabricate(:mailinglist_mirror_category)
      topic = Fabricate(:topic, category: category)
      user = Fabricate(:staged)
      _post = Fabricate(:post, user: user, topic: topic)
      reply = Fabricate(:post, topic: topic, reply_to_post_number: 1)

      NotificationEmailer.expects(:process_notification).never
      expect { PostAlerter.post_created(reply) }.not_to change(user.notifications, :count)

      category.mailinglist_mirror = false
      NotificationEmailer.expects(:process_notification).once
      expect { PostAlerter.post_created(reply) }.to change(user.notifications, :count).by(1)
    end

    it "creates a notification of type `replied` instead of `posted` for the topic author if they're watching the topic" do
      Jobs.run_immediately!

      u1 = Fabricate(:admin)
      u2 = Fabricate(:admin)

      topic = create_topic(user: u1)

      u1.notifications.destroy_all

      expect do
        create_post(topic: topic, user: u2)
      end.to change { u1.reload.notifications.count }.by(1)
      expect(u1.notifications.exists?(
        topic_id: topic.id,
        notification_type: Notification.types[:replied],
        post_number: 1,
        read: false
      )).to eq(true)
    end

    it "it doesn't notify about small action posts when the topic author is watching the topic " do
      Jobs.run_immediately!

      u1 = Fabricate(:admin)
      u2 = Fabricate(:admin)

      topic = create_topic(user: u1)

      u1.notifications.destroy_all

      expect do
        topic.update_status("closed", true, u2, message: "hello world")
      end.not_to change { u1.reload.notifications.count }
    end
  end

  context "with category" do
    context "with watching" do
      it "triggers :before_create_notifications_for_users" do
        topic = Fabricate(:topic, category: category)
        post = Fabricate(:post, topic: topic)
        level = CategoryUser.notification_levels[:watching]
        CategoryUser.set_notification_level_for_category(user, level, category.id)
        events = DiscourseEvent.track_events do
          PostAlerter.post_created(post)
        end
        expect(events).to include(event_name: :before_create_notifications_for_users, params: [[user], post])
      end

      it "notifies staff about whispered post" do
        topic = Fabricate(:topic, category: category)
        level = CategoryUser.notification_levels[:watching]
        CategoryUser.set_notification_level_for_category(admin, level, category.id)
        CategoryUser.set_notification_level_for_category(user, level, category.id)
        whispered_post = Fabricate(:post, user: Fabricate(:admin), topic: topic, post_type: Post.types[:whisper])
        expect {
          PostAlerter.post_created(whispered_post)
        }.to add_notification(admin, :watching_category_or_tag)
        expect {
          PostAlerter.post_created(whispered_post)
        }.not_to add_notification(user, :watching_category_or_tag)
      end

      it "notifies a staged user about a private post, but only if the user has access" do
        staged_member = Fabricate(:staged)
        staged_non_member = Fabricate(:staged)
        group_member = Fabricate(:user)

        group.add(group_member)
        group.add(staged_member)

        private_category = Fabricate(
          :private_category, group: group,
                             email_in: 'test@test.com', email_in_allow_strangers: false
        )

        level = CategoryUser.notification_levels[:watching]
        CategoryUser.set_notification_level_for_category(group_member, level, private_category.id)
        CategoryUser.set_notification_level_for_category(staged_member, level, private_category.id)
        CategoryUser.set_notification_level_for_category(staged_non_member, level, private_category.id)

        topic = Fabricate(:topic, category: private_category, user: group_member)
        post = Fabricate(:post, topic: topic)

        expect {
          PostAlerter.post_created(post)
        }.to add_notification(staged_member, :watching_category_or_tag)
          .and not_add_notification(staged_non_member, :watching_category_or_tag)
      end

      it "does not update existing unread notification" do
        CategoryUser.set_notification_level_for_category(user, CategoryUser.notification_levels[:watching], category.id)
        topic = Fabricate(:topic, category: category)

        post = Fabricate(:post, topic: topic)
        PostAlerter.post_created(post)
        notification = Notification.last
        expect(notification.topic_id).to eq(topic.id)
        expect(notification.post_number).to eq(1)

        post = Fabricate(:post, topic: topic)
        PostAlerter.post_created(post)
        notification = Notification.last
        expect(notification.topic_id).to eq(topic.id)
        expect(notification.post_number).to eq(1)
        notification_data = JSON.parse(notification.data)
        expect(notification_data["display_username"]).to eq(I18n.t("embed.replies", count: 2))
      end
    end
  end

  context "with tags" do
    context "with watching" do
      it "triggers :before_create_notifications_for_users" do
        tag = Fabricate(:tag)
        topic = Fabricate(:topic, tags: [tag])
        post = Fabricate(:post, topic: topic)
        level = TagUser.notification_levels[:watching]
        TagUser.change(user.id, tag.id, level)
        events = DiscourseEvent.track_events do
          PostAlerter.post_created(post)
        end
        expect(events).to include(event_name: :before_create_notifications_for_users, params: [[user], post])
      end

      it "does not update existing unread notification" do
        tag = Fabricate(:tag)
        TagUser.change(user.id, tag.id, TagUser.notification_levels[:watching])
        topic = Fabricate(:topic, tags: [tag])

        post = Fabricate(:post, topic: topic)
        PostAlerter.post_created(post)
        notification = Notification.last
        expect(notification.topic_id).to eq(topic.id)
        expect(notification.post_number).to eq(1)

        post = Fabricate(:post, topic: topic)
        PostAlerter.post_created(post)
        notification = Notification.last
        expect(notification.topic_id).to eq(topic.id)
        expect(notification.post_number).to eq(1)
        notification_data = JSON.parse(notification.data)
        expect(notification_data["display_username"]).to eq(I18n.t("embed.replies", count: 2))
      end

      it "does not add notification if user does not belong to tag group with permissions" do
        tag = Fabricate(:tag)
        topic = Fabricate(:topic, tags: [tag])
        post = Fabricate(:post, topic: topic)

        tag_group = TagGroup.new(name: 'Only visible to group', tag_names: [tag.name])
        tag_group.permissions = [[group.id, TagGroupPermission.permission_types[:full]]]
        tag_group.save!

        TagUser.change(user.id, tag.id, TagUser.notification_levels[:watching])

        expect { PostAlerter.post_created(post) }.not_to change { Notification.count }
      end

      it "adds notification if user belongs to tag group with permissions" do
        tag = Fabricate(:tag)
        topic = Fabricate(:topic, tags: [tag])
        post = Fabricate(:post, topic: topic)
        tag_group = Fabricate(:tag_group, tags: [tag])
        Fabricate(:group_user, group: group, user: user)
        Fabricate(:tag_group_permission, tag_group: tag_group, group: group)

        TagUser.change(user.id, tag.id, TagUser.notification_levels[:watching])

        expect { PostAlerter.post_created(post) }.to change { Notification.count }.by(1)
      end
    end

    context "with on change" do
      fab!(:user) { Fabricate(:user) }
      fab!(:other_tag) { Fabricate(:tag) }
      fab!(:watched_tag) { Fabricate(:tag) }

      before do
        SiteSetting.tagging_enabled = true
        Jobs.run_immediately!
        TagUser.change(user.id, watched_tag.id, TagUser.notification_levels[:watching_first_post])
        TopicUser.change(Fabricate(:user).id, post.topic.id, notification_level: TopicUser.notification_levels[:watching])
      end

      it "triggers a notification" do
        expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(0)

        expect { PostRevisor.new(post).revise!(Fabricate(:user), tags: [other_tag.name, watched_tag.name]) }.to change { Notification.where(user_id: user.id).count }.by(1)
        expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(1)

        expect { PostRevisor.new(post).revise!(Fabricate(:user), tags: [watched_tag.name, other_tag.name]) }.not_to change { Notification.count }
        expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(1)
      end

      it "doesn't trigger a notification if topic is unlisted" do
        post.topic.update_column(:visible, false)

        expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(0)

        PostRevisor.new(post).revise!(Fabricate(:user), tags: [other_tag.name, watched_tag.name])
        expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(0)
      end
    end

    context "with private message" do
      fab!(:post) { Fabricate(:private_message_post) }
      fab!(:other_tag) { Fabricate(:tag) }
      fab!(:other_tag2) { Fabricate(:tag) }
      fab!(:other_tag3) { Fabricate(:tag) }
      fab!(:user) { Fabricate(:user) }
      fab!(:staged) { Fabricate(:staged) }

      before do
        SiteSetting.tagging_enabled = true
        SiteSetting.pm_tags_allowed_for_groups = "1|2|3"
        Jobs.run_immediately!
        TopicUser.change(user.id, post.topic.id, notification_level: TopicUser.notification_levels[:watching])
        TopicUser.change(staged.id, post.topic.id, notification_level: TopicUser.notification_levels[:watching])
        TopicUser.change(admin.id, post.topic.id, notification_level: TopicUser.notification_levels[:watching])
        TagUser.change(staged.id, other_tag.id, TagUser.notification_levels[:watching])
        TagUser.change(admin.id, other_tag3.id, TagUser.notification_levels[:watching])
        post.topic.allowed_users << user
        post.topic.allowed_users << staged
      end

      it "only notifies staff watching added tag" do
        expect(PostRevisor.new(post).revise!(Fabricate(:admin), tags: [other_tag.name])).to be true
        expect(Notification.where(user_id: staged.id).count).to eq(0)
        expect(PostRevisor.new(post).revise!(Fabricate(:admin), tags: [other_tag2.name])).to be true
        expect(Notification.where(user_id: admin.id).count).to eq(0)
        expect(PostRevisor.new(post).revise!(Fabricate(:admin), tags: [other_tag3.name])).to be true
        expect(Notification.where(user_id: admin.id).count).to eq(1)
      end
    end

    context "with tag groups" do
      fab!(:tag)  { Fabricate(:tag) }
      fab!(:user) { Fabricate(:user) }
      fab!(:topic) { Fabricate(:topic, tags: [tag]) }
      fab!(:post) { Fabricate(:post, topic: topic) }

      shared_examples "tag user with notification level" do |notification_level, notification_type|
        it "notifies a user who is watching a tag that does not belong to a tag group" do
          TagUser.change(user.id, tag.id, TagUser.notification_levels[notification_level])
          PostAlerter.post_created(post)
          expect(user.notifications.where(notification_type: Notification.types[notification_type]).count).to eq(1)
        end

        it "does not notify a user watching a tag with tag group permissions that he does not belong to" do
          tag_group = Fabricate(:tag_group, tags: [tag], permissions: { group.name => 1 })

          TagUser.change(user.id, tag.id, TagUser.notification_levels[notification_level])

          PostAlerter.post_created(post)

          expect(user.notifications.where(notification_type: Notification.types[notification_type]).count).to eq(0)
        end

        it "notifies a user watching a tag with tag group permissions that he belongs to" do
          Fabricate(:group_user, group: group, user: user)

          TagUser.change(user.id, tag.id, TagUser.notification_levels[notification_level])

          PostAlerter.post_created(post)

          expect(user.notifications.where(notification_type: Notification.types[notification_type]).count).to eq(1)
        end

        it "notifies a staff watching a tag with tag group permissions that he does not belong to" do
          tag_group = Fabricate(:tag_group, tags: [tag])
          Fabricate(:tag_group_permission, tag_group: tag_group, group: group)
          staff_group = Group.find(Group::AUTO_GROUPS[:staff])
          Fabricate(:group_user, group: staff_group, user: user)

          TagUser.change(user.id, tag.id, TagUser.notification_levels[notification_level])

          PostAlerter.post_created(post)

          expect(user.notifications.where(notification_type: Notification.types[notification_type]).count).to eq(1)
        end
      end

      context "with :watching notification level" do
        include_examples "tag user with notification level", :watching, :watching_category_or_tag
      end

      context "with :watching_first_post notification level" do
        include_examples "tag user with notification level", :watching_first_post, :watching_first_post
      end
    end
  end

  describe '#extract_linked_users' do
    fab!(:post) { Fabricate(:post, topic: topic) }
    fab!(:post2) { Fabricate(:post) }

    describe 'when linked post has been deleted' do
      let(:topic_link) do
        TopicLink.create!(
          url: "/t/#{topic.id}",
          topic_id: topic.id,
          link_topic_id: post2.topic.id,
          link_post_id: nil,
          post_id: post.id,
          user: user,
          domain: 'test.com'
        )
      end

      it 'should use the first post of the topic' do
        topic_link
        expect(PostAlerter.new.extract_linked_users(post.reload)).to eq([post2.user])
      end
    end
  end

  describe '#notify_post_users' do
    fab!(:post) { Fabricate(:post, topic: topic) }
    fab!(:last_editor) { Fabricate(:user) }
    fab!(:tag) { Fabricate(:tag) }
    fab!(:category) { Fabricate(:category) }

    it 'creates single edit notification when post is modified' do
      TopicUser.create!(
        user_id: user.id,
        topic_id: topic.id,
        notification_level: TopicUser.notification_levels[:watching],
        last_read_post_number: post.post_number
      )

      PostRevisor.new(post).revise!(last_editor, tags: [tag.name])
      PostAlerter.new.notify_post_users(post, [])
      expect(Notification.count).to eq(1)
      expect(Notification.last.notification_type).to eq(Notification.types[:edited])
      expect(JSON.parse(Notification.last.data)["display_username"]).to eq(last_editor.username)

      PostAlerter.new.notify_post_users(post, [])
      expect(Notification.count).to eq(1)
    end

    it 'creates posted notification when Sidekiq is slow' do
      CategoryUser.set_notification_level_for_category(user, CategoryUser.notification_levels[:watching], category.id)

      post = PostCreator.create!(
        Fabricate(:user),
        title: "one of my first topics",
        raw: "one of my first posts",
        category: category.id
      )

      TopicUser.change(user, post.topic_id, last_read_post_number: post.post_number)

      # Manually run job after the user read the topic to simulate a slow
      # Sidekiq.
      job_args = Jobs::PostAlert.jobs[0]['args'][0]
      expect { Jobs::PostAlert.new.execute(job_args.with_indifferent_access) }
        .to change { Notification.count }.by(1)

      expect(Notification.last.notification_type).to eq(Notification.types[:posted])
    end
  end

  context "with SMTP (group_smtp_email)" do
    before do
      SiteSetting.enable_smtp = true
      SiteSetting.email_in = true
      Jobs.run_immediately!
    end

    fab!(:group) do
      Fabricate(
        :group,
        smtp_server: "smtp.gmail.com",
        smtp_port: 587,
        smtp_ssl: true,
        imap_server: "imap.gmail.com",
        imap_port: 993,
        imap_ssl: true,
        email_username: "discourse@example.com",
        email_password: "password",
        smtp_enabled: true,
        imap_enabled: true
      )
    end

    def create_post_with_incoming
      raw_mail = <<~EMAIL
      From: Foo <foo@discourse.org>
      To: discourse@example.com
      Cc: bar@discourse.org, jim@othersite.com
      Subject: Full email group username flow
      Date: Fri, 15 Jan 2021 00:12:43 +0100
      Message-ID: <u4w8c9r4y984yh98r3h69873@example.com.mail>
      Mime-Version: 1.0
      Content-Type: text/plain
      Content-Transfer-Encoding: 7bit

      This is the first email.
      EMAIL

      Email::Receiver.new(raw_mail, {}).process!
    end

    it "does not error if SMTP is enabled and the topic has no incoming email or allowed groups" do
      expect { PostAlerter.new.after_save_post(post, true) }.not_to raise_error
    end

    it "does not error if SMTP is enabled and the topic has no incoming email but does have an allowed group" do
      TopicAllowedGroup.create(topic: private_message_topic, group: group)
      expect { PostAlerter.new.after_save_post(post, true) }.not_to raise_error
    end

    it "does not error if SMTP is enabled and the topic has no incoming email but has multiple allowed groups" do
      TopicAllowedGroup.create(topic: private_message_topic, group: group)
      TopicAllowedGroup.create(topic: private_message_topic, group: Fabricate(:group))
      expect { PostAlerter.new.after_save_post(post, true) }.not_to raise_error
    end

    it "sends a group smtp email because SMTP is enabled for the site and the group" do
      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic
      post = Fabricate(:post, topic: topic)
      expect { PostAlerter.new.after_save_post(post, true) }.to change { ActionMailer::Base.deliveries.size }.by(1)
      email = ActionMailer::Base.deliveries.last
      expect(email.from).to include(group.email_username)
      expect(email.to).to contain_exactly(topic.reload.topic_allowed_users.order(:created_at).first.user.email)
      expect(email.cc).to match_array(["bar@discourse.org", "jim@othersite.com"])
      expect(email.subject).to eq("Re: #{topic.title}")
    end

    it "sends a group smtp email when the original group has had SMTP disabled and there is an additional topic allowed group" do
      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic
      other_allowed_group = Fabricate(:smtp_group)
      TopicAllowedGroup.create(group: other_allowed_group, topic: topic)
      post = Fabricate(:post, topic: topic)
      group.update!(smtp_enabled: false)

      expect { PostAlerter.new.after_save_post(post, true) }.to change { ActionMailer::Base.deliveries.size }.by(1)

      email = ActionMailer::Base.deliveries.last
      expect(email.from).to include(other_allowed_group.email_username)
      expect(email.to).to contain_exactly(topic.reload.topic_allowed_users.order(:created_at).first.user.email)
      expect(email.cc).to match_array(["bar@discourse.org", "jim@othersite.com"])
      expect(email.subject).to eq("Re: #{topic.title}")
    end

    it "does not send a group smtp email if smtp is not enabled for the group" do
      group.update!(smtp_enabled: false)
      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic
      post = Fabricate(:post, topic: topic)
      expect { PostAlerter.new.after_save_post(post, true) }.not_to change { ActionMailer::Base.deliveries.size }
    end

    it "does not send a group smtp email if SiteSetting.enable_smtp is false" do
      SiteSetting.enable_smtp = false
      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic
      post = Fabricate(:post, topic: topic)
      expect { PostAlerter.new.after_save_post(post, true) }.not_to change { ActionMailer::Base.deliveries.size }
    end

    it "does not send group smtp emails for a whisper" do
      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic
      post = Fabricate(:post, topic: topic, post_type: Post.types[:whisper])
      expect { PostAlerter.new.after_save_post(post, true) }.not_to change { ActionMailer::Base.deliveries.size }
    end

    it "sends the group smtp email job with a delay of personal_email_time_window_seconds" do
      freeze_time
      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic
      post = Fabricate(:post, topic: topic)
      PostAlerter.new.after_save_post(post, true)
      job_enqueued?(
        job: :group_smtp_email,
        args: {
          group_id: group.id,
          post_id: post.id,
          email: topic.reload.topic_allowed_users.order(:created_at).first.user.email,
          cc_emails: ["bar@discourse.org", "jim@othersite.com"]
        },
        at: Time.zone.now + SiteSetting.personal_email_time_window_seconds.seconds
      )
    end

    it "does not send a group smtp email for anyone if the reply post originates from an incoming email that is auto generated" do
      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic
      post = Fabricate(:post, topic: topic)
      Fabricate(:incoming_email, post: post, topic: topic, is_auto_generated: true)
      expect_not_enqueued_with(job: :group_smtp_email) do
        expect { PostAlerter.new.after_save_post(post, true) }.not_to change { ActionMailer::Base.deliveries.size }
      end
    end

    it "skips sending a notification email to the group and all other email addresses that are _not_ members of the group,
    sends a group_smtp_email instead" do
      NotificationEmailer.enable

      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic

      group_user1 = Fabricate(:group_user, group: group)
      group_user2 = Fabricate(:group_user, group: group)
      TopicUser.create(user: group_user1.user, notification_level: TopicUser.notification_levels[:watching], topic: topic)
      post = Fabricate(:post, topic: topic.reload)

      # Sends an email for:
      #
      # 1. the group user that is watching the post (but does not send this email with group SMTO)
      # 2. the group smtp email to notify all topic_users not in the group
      expect { PostAlerter.new.after_save_post(post, true) }.to change {
        ActionMailer::Base.deliveries.size
      }.by(2).and change { Notification.count }.by(2)

      # The group smtp email
      email = ActionMailer::Base.deliveries.first
      expect(email.from).to eq([group.email_username])
      expect(email.to).to contain_exactly("foo@discourse.org")
      expect(email.cc).to match_array(["bar@discourse.org", "jim@othersite.com"])
      expect(email.subject).to eq("Re: #{topic.title}")

      # The watching group user notification email
      email = ActionMailer::Base.deliveries.last
      expect(email.from).to eq([SiteSetting.notification_email])
      expect(email.to).to contain_exactly(group_user1.user.email)
      expect(email.cc).to eq(nil)
      expect(email.subject).to eq("[Discourse] [PM] #{topic.title}")
    end

    it "skips sending a notification email to the cc address that was added on the same post with an incoming email" do
      NotificationEmailer.enable

      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic

      post = Fabricate(:post, topic: topic.reload)
      expect { PostAlerter.new.after_save_post(post, true) }.to change {
        ActionMailer::Base.deliveries.size
      }.by(1).and change { Notification.count }.by(1)
      email = ActionMailer::Base.deliveries.last

      # the reply post from someone who was emailed
      reply_raw_mail = <<~EMAIL
      From: Bar <bar@discourse.org>
      To: discourse@example.com
      Cc: someothernewcc@baz.com, finalnewcc@doom.com
      Subject: #{email.subject}
      Date: Fri, 16 Jan 2021 00:12:43 +0100
      Message-ID: <sdugj3o4iyu4832x3487@discourse.org.mail>
      In-Reply-To: #{email.message_id}
      Mime-Version: 1.0
      Content-Type: text/plain
      Content-Transfer-Encoding: 7bit

      Hey here is my reply!
      EMAIL

      reply_post_from_email = nil
      expect {
        reply_post_from_email = Email::Receiver.new(reply_raw_mail, {}).process!
      }.to change {
        User.count # the two new cc addresses have users created
      }.by(2).and change {
        TopicAllowedUser.where(topic: topic).count # and they are added as topic allowed users
      }.by(2).and change {
        # but they are not sent emails because they were cc'd on an email, only jim@othersite.com
        # is emailed because he is a topic allowed user cc'd on the _original_ email and he is not
        # the one creating the post, and foo@discourse.org, who is the OP of the topic
        ActionMailer::Base.deliveries.size
      }.by(1).and change {
        Notification.count # and they are still sent their normal discourse notification
      }.by(2)

      email = ActionMailer::Base.deliveries.last

      expect(email.to).to eq(["foo@discourse.org"])
      expect(email.cc).to eq(["jim@othersite.com"])
      expect(email.from).to eq([group.email_username])
      expect(email.subject).to eq("Re: #{topic.title}")
    end

    it "handles the OP of the topic replying by email and sends a group email to the other topic allowed users successfully" do
      NotificationEmailer.enable

      incoming_email_post = create_post_with_incoming
      topic = incoming_email_post.topic
      post = Fabricate(:post, topic: topic.reload)
      expect { PostAlerter.new.after_save_post(post, true) }.to change {
        ActionMailer::Base.deliveries.size
      }.by(1).and change { Notification.count }.by(1)
      email = ActionMailer::Base.deliveries.last

      # the reply post from someone who was emailed
      reply_raw_mail = <<~EMAIL
      From: Foo <foo@discourse.org>
      To: discourse@example.com
      Cc: someothernewcc@baz.com, finalnewcc@doom.com
      Subject: #{email.subject}
      Date: Fri, 16 Jan 2021 00:12:43 +0100
      Message-ID: <sgk094238uc0348c334483@discourse.org.mail>
      In-Reply-To: #{email.message_id}
      Mime-Version: 1.0
      Content-Type: text/plain
      Content-Transfer-Encoding: 7bit

      I am ~~Commander Shepherd~~ the OP and I approve of this message.
      EMAIL

      reply_post_from_email = nil
      expect {
        reply_post_from_email = Email::Receiver.new(reply_raw_mail, {}).process!
      }.to change {
        User.count # the two new cc addresses have users created
      }.by(2).and change {
        TopicAllowedUser.where(topic: topic).count # and they are added as topic allowed users
      }.by(2).and change {
        # but they are not sent emails because they were cc'd on an email, only jim@othersite.com
        # is emailed because he is a topic allowed user cc'd on the _original_ email and he is not
        # the one creating the post
        ActionMailer::Base.deliveries.size
      }.by(1).and change {
        Notification.count # and they are still sent their normal discourse notification
      }.by(2)

      email = ActionMailer::Base.deliveries.last

      expect(email.to).to eq(["bar@discourse.org"])
      expect(email.cc).to eq(["jim@othersite.com"])
      expect(email.from).to eq([group.email_username])
      expect(email.subject).to eq("Re: #{topic.title}")
    end

    it "handles the OP of the topic replying by email and cc'ing new people, and does not send a group SMTP email to those newly cc'd users" do
      NotificationEmailer.enable

      # this is a special case where we are not CC'ing on the original email,
      # only on the follow up email
      raw_mail = <<~EMAIL
      From: Foo <foo@discourse.org>
      To: discourse@example.com
      Subject: Full email group username flow
      Date: Fri, 14 Jan 2021 00:12:43 +0100
      Message-ID: <f4832ujfc3498u398i3@example.com.mail>
      Mime-Version: 1.0
      Content-Type: text/plain
      Content-Transfer-Encoding: 7bit

      This is the first email.
      EMAIL

      incoming_email_post = Email::Receiver.new(raw_mail, {}).process!
      topic = incoming_email_post.topic
      post = Fabricate(:post, topic: topic.reload)
      expect { PostAlerter.new.after_save_post(post, true) }.to change {
        ActionMailer::Base.deliveries.size
      }.by(1).and change { Notification.count }.by(1)
      email = ActionMailer::Base.deliveries.last

      # the reply post from the OP, cc'ing new people in
      reply_raw_mail = <<~EMAIL
      From: Foo <foo@discourse.org>
      To: discourse@example.com
      Cc: someothernewcc@baz.com, finalnewcc@doom.com
      Subject: #{email.subject}
      Date: Fri, 16 Jan 2021 00:12:43 +0100
      Message-ID: <3849cu9843yncr9834yr9348x934@discourse.org.mail>
      In-Reply-To: #{email.message_id}
      Mime-Version: 1.0
      Content-Type: text/plain
      Content-Transfer-Encoding: 7bit

      I am inviting my mates to this email party.
      EMAIL

      reply_post_from_email = nil
      expect {
        reply_post_from_email = Email::Receiver.new(reply_raw_mail, {}).process!
      }.to change {
        User.count # the two new cc addresses have users created
      }.by(2).and change {
        TopicAllowedUser.where(topic: topic).count # and they are added as topic allowed users
      }.by(2).and not_change {
        # but they are not sent emails because they were cc'd on an email.
        # no group smtp message is sent because the OP is not sent an email,
        # they made this post.
        ActionMailer::Base.deliveries.size
      }.and change {
        Notification.count # and they are still sent their normal discourse notification
      }.by(2)

      last_email = ActionMailer::Base.deliveries.last
      expect(email).to eq(last_email)
    end
  end

  describe 'storing custom data' do
    let(:custom_data) { 'custom_string' }

    it 'stores custom data inside a notification' do
      PostAlerter.new.create_notification(
        admin,
        Notification.types[:liked],
        post,
        custom_data: { custom_key: custom_data }
      )

      liked_notification = Notification.where(notification_type: Notification.types[:liked]).last

      expect(liked_notification.data_hash[:custom_key]).to eq(custom_data)
    end
  end

  it "does not create notifications for PMs if not invited" do
    SiteSetting.pm_tags_allowed_for_groups = "#{Group::AUTO_GROUPS[:everyone]}"
    watching_first_post_tag = Fabricate(:tag)
    TagUser.change(admin.id, watching_first_post_tag.id, TagUser.notification_levels[:watching_first_post])
    watching_tag = Fabricate(:tag)
    TagUser.change(admin.id, watching_tag.id, TagUser.notification_levels[:watching])

    post = create_post(tags: [watching_first_post_tag.name, watching_tag.name], archetype: Archetype.private_message, target_usernames: "#{evil_trout.username}")
    expect { PostAlerter.new.after_save_post(post, true) }.to change { Notification.count }.by(1)

    notification = Notification.last
    expect(notification.user).to eq(evil_trout)
    expect(notification.notification_type).to eq(Notification.types[:private_message])
    expect(notification.topic).to eq(post.topic)
    expect(notification.post_number).to eq(1)
  end

  it "does not create multiple notifications for same post" do
    category = Fabricate(:category)
    CategoryUser.set_notification_level_for_category(
      user,
      NotificationLevels.all[:tracking],
      category.id,
    )
    watching_first_post_tag = Fabricate(:tag)
    TagUser.change(user.id, watching_first_post_tag.id, TagUser.notification_levels[:watching_first_post])
    watching_tag = Fabricate(:tag)
    TagUser.change(user.id, watching_tag.id, TagUser.notification_levels[:watching])

    post = create_post(category: category, tags: [watching_first_post_tag.name, watching_tag.name])
    expect { PostAlerter.new.after_save_post(post, true) }.to change { Notification.count }.by(1)

    notification = Notification.last
    expect(notification.user).to eq(user)
    expect(notification.notification_type).to eq(Notification.types[:watching_category_or_tag])
    expect(notification.topic).to eq(post.topic)
    expect(notification.post_number).to eq(1)
  end

  it 'triggers all discourse events' do
    expected_events = [
      :post_alerter_before_mentions,
      :post_alerter_before_replies,
      :post_alerter_before_quotes,
      :post_alerter_before_linked,
      :post_alerter_before_post,
      :post_alerter_before_first_post,
      :post_alerter_after_save_post,
    ]

    events = DiscourseEvent.track_events do
      PostAlerter.new.after_save_post(post, true)
    end

    # Expect all the notification events are called
    # There are some other events triggered from outside after_save_post
    expect(events.map { |e| e[:event_name] }).to include(*expected_events)

    # Expect each notification event is called with the right parameters
    events.each do |event|
      if expected_events.include?(event[:event_name])
        expect(event[:params]).to eq([post, true, [post.user]])
      end
    end
  end
end