FEATURE: Enable optional support for threading slack posts (#38)

When creating a new Discourse post from slack with the `post` feature, record the
slack `ts` thread ID for the resulting topic post using an HTML comment to pass
the `ts` through.

When notifying slack of new Discourse posts, record the slack `ts` thread ID in
the post's topic if it has not yet been recorded. (Normally, this will be done
for the topic post, except where notifications are being posted for old topics
before this feature was created.)

Add a new rule filter `thread` which posts threaded responses to slack if there
is a `ts` recorded for the post topic.

Modify the `trigger_notifications` interface to enable other integrations to
implement similar functionality.

Present the `thread` rule in the help text and admin UI only for the slack
providers.

https://meta.discourse.org/t/optionally-threading-posts-to-parent-topic-in-slack-integration/150759

app/controllers/chat_controller.rb

@@ -34,7 +34,7 @@ class DiscourseChat::ChatController < ApplicationController
 
       post = Topic.find(topic_id.to_i).posts.first
 
-      provider.trigger_notification(post, channel)
+      provider.trigger_notification(post, channel, nil)
 
       render json: success_json
     rescue Discourse::InvalidParameters, ActiveRecord::RecordNotFound => e

app/helpers/helper.rb

@@ -13,7 +13,7 @@ module DiscourseChat
       error_text = I18n.t("chat_integration.provider.#{provider}.parse_error")
 
       case cmd
-      when "watch", "follow", "mute"
+      when "thread", "watch", "follow", "mute"
         return error_text if tokens.empty?
         # If the first token in the command is a tag, this rule applies to all categories
         category_name = tokens[0].start_with?('tag:') ? nil : tokens.shift

app/models/rule.rb

@@ -31,15 +31,16 @@ class DiscourseChat::Rule < DiscourseChat::PluginModel
     "
       CASE
       WHEN value::json->>'filter' = 'mute' THEN 1
-      WHEN value::json->>'filter' = 'watch' THEN 2
-      WHEN value::json->>'filter' = 'follow' THEN 3
+      WHEN value::json->>'filter' = 'thread' THEN 2
+      WHEN value::json->>'filter' = 'watch' THEN 3
+      WHEN value::json->>'filter' = 'follow' THEN 4
      END
     ")
   }
 
   after_initialize :init_filter
 
-  validates :filter, inclusion: { in: %w(watch follow mute),
+  validates :filter, inclusion: { in: %w(thread watch follow mute),
                                   message: "%{value} is not a valid filter" }
 
   validates :type, inclusion: { in: %w(normal group_message group_mention),

app/services/manager.rb

@@ -52,7 +52,7 @@ module DiscourseChat
 
       # Sort by order of precedence
       t_prec = { 'group_message' => 0, 'group_mention' => 1, 'normal' => 2 } # Group things win
-      f_prec = { 'mute' => 0, 'watch' => 1, 'follow' => 2 } #(mute always wins; watch beats follow)
+      f_prec = { 'mute' => 0, 'thread' => 1, 'watch' => 2, 'follow' => 3 } #(mute always wins; thread beats watch beats follow)
       sort_func = proc { |a, b| [t_prec[a.type], f_prec[a.filter]] <=> [t_prec[b.type], f_prec[b.filter]] }
       matching_rules = matching_rules.sort(&sort_func)
 
@@ -80,7 +80,7 @@ module DiscourseChat
         next unless is_enabled = ::DiscourseChat::Provider.is_enabled(provider)
 
         begin
-          provider.trigger_notification(post, channel)
+          provider.trigger_notification(post, channel, rule)
           channel.update_attribute('error_key', nil) if channel.error_key
         rescue => e
           if e.class == (DiscourseChat::ProviderError) && e.info.key?(:error_key) && !e.info[:error_key].nil?

assets/javascripts/admin/models/rule.js.es6

@@ -6,23 +6,38 @@ import {
 } from "discourse-common/utils/decorators";
 
 export default RestModel.extend({
-  available_filters: [
-    {
-      id: "watch",
-      name: I18n.t("chat_integration.filter.watch"),
-      icon: "exclamation-circle"
-    },
-    {
-      id: "follow",
-      name: I18n.t("chat_integration.filter.follow"),
-      icon: "circle"
-    },
-    {
-      id: "mute",
-      name: I18n.t("chat_integration.filter.mute"),
-      icon: "times-circle"
+  @computed("channel.provider")
+  available_filters(provider) {
+    const available = [];
+
+    if (provider === "slack") {
+      available.push({
+        id: "thread",
+        name: I18n.t("chat_integration.filter.thread"),
+        icon: "chevron-right"
+      });
     }
-  ],
+
+    available.push(
+      {
+        id: "watch",
+        name: I18n.t("chat_integration.filter.watch"),
+        icon: "exclamation-circle"
+      },
+      {
+        id: "follow",
+        name: I18n.t("chat_integration.filter.follow"),
+        icon: "circle"
+      },
+      {
+        id: "mute",
+        name: I18n.t("chat_integration.filter.mute"),
+        icon: "times-circle"
+      }
+    );
+
+    return available;
+  },
 
   available_types: [
     { id: "normal", name: I18n.t("chat_integration.type.normal") },

assets/javascripts/admin/routes/admin-plugins-chat-provider.js.es6

@@ -18,7 +18,7 @@ export default DiscourseRoute.extend({
           "rules",
           channel.rules.map(rule => {
             rule = this.store.createRecord("rule", rule);
-            rule.channel = channel;
+            rule.set("channel", channel);
             return rule;
           })
         );

config/locales/client.en.yml

@@ -36,6 +36,7 @@ en:
         mute: 'Mute'
         follow: 'First post only'
         watch: 'All posts and replies'
+        thread: 'All posts with threaded replies'
       rule_table:
         filter: "Filter"
         category: "Category"

config/locales/server.en.yml

@@ -122,8 +122,9 @@ en:
           tag: "The *%{name}* tag cannot be found."
           category: "The *%{name}* category cannot be found. Available categories: *%{list}*"
         help: |
-          *New rule:* `/discourse [watch|follow|mute] [category] [tag:name]`
+          *New rule:* `/discourse [thread|watch|follow|mute] [category] [tag:name]`
           (you must specify a rule type and at least one category or tag)
+          - *thread* – notify this channel for new topics, thread replies if possible
           - *watch* – notify this channel for new topics and new replies
           - *follow* – notify this channel for new topics
           - *mute* – block notifications to this channel

lib/discourse_chat/provider/discord/discord_provider.rb

@@ -63,7 +63,7 @@ module DiscourseChat
         message
       end
 
-      def self.trigger_notification(post, channel)
+      def self.trigger_notification(post, channel, rule)
         # Adding ?wait=true means that we actually get a success/failure response, rather than returning asynchronously
         webhook_url = "#{channel.data['webhook_url']}?wait=true"
         message = generate_discord_message(post)

lib/discourse_chat/provider/flowdock/flowdock_provider.rb

@@ -48,7 +48,7 @@ module DiscourseChat::Provider::FlowdockProvider
     message
   end
 
-  def self.trigger_notification(post, channel)
+  def self.trigger_notification(post, channel, rule)
     flow_token = channel.data["flow_token"]
     message = generate_flowdock_message(post, flow_token)
     response = send_message("https://api.flowdock.com/messages", message)

lib/discourse_chat/provider/gitter/gitter_provider.rb

@@ -10,7 +10,7 @@ module DiscourseChat
         { key: "webhook_url", regex: '^https://webhooks\.gitter\.im/e/\S+$', unique: true, hidden: true }
       ]
 
-      def self.trigger_notification(post, channel)
+      def self.trigger_notification(post, channel, rule)
         message = gitter_message(post)
         response = Net::HTTP.post_form(URI(channel.data['webhook_url']), message: message)
         unless response.kind_of? Net::HTTPSuccess

lib/discourse_chat/provider/groupme/groupme_provider.rb

@@ -71,7 +71,7 @@ module DiscourseChat::Provider::GroupmeProvider
     end
   end
 
-  def self.trigger_notification(post, channel)
+  def self.trigger_notification(post, channel, rule)
     data_package = generate_groupme_message(post)
     self.send_via_webhook(data_package, channel)
   end

lib/discourse_chat/provider/matrix/matrix_provider.rb

@@ -56,7 +56,7 @@ module DiscourseChat
         message
       end
 
-      def self.trigger_notification(post, channel)
+      def self.trigger_notification(post, channel, rule)
         message = generate_matrix_message(post)
 
         response = send_message(channel.data['room_id'], message)

lib/discourse_chat/provider/mattermost/mattermost_provider.rb

@@ -75,7 +75,7 @@ module DiscourseChat
         message
       end
 
-      def self.trigger_notification(post, channel)
+      def self.trigger_notification(post, channel, rule)
         channel_id = channel.data['identifier']
         message = mattermost_message(post, channel_id)
 

lib/discourse_chat/provider/rocketchat/rocketchat_provider.rb

@@ -68,7 +68,7 @@ module DiscourseChat::Provider::RocketchatProvider
 
   end
 
-  def self.trigger_notification(post, channel)
+  def self.trigger_notification(post, channel, rule)
     channel_id = channel.data['identifier']
     message = rocketchat_message(post, channel_id)
 

lib/discourse_chat/provider/slack/slack_provider.rb

@@ -2,6 +2,7 @@
 
 module DiscourseChat::Provider::SlackProvider
   PROVIDER_NAME = "slack".freeze
+  THREAD = "thread".freeze
 
   PROVIDER_ENABLED_SETTING = :chat_integration_slack_enabled
 
@@ -9,6 +10,18 @@ module DiscourseChat::Provider::SlackProvider
                         { key: "identifier", regex: '^[@#]?\S*$', unique: true }
                        ]
 
+  require_dependency 'topic'
+  ::Topic.register_custom_field_type(DiscourseChat::Provider::SlackProvider::THREAD, :text)
+
+  class ::Topic
+    def slack_thread_id=(ts)
+      self.custom_fields[DiscourseChat::Provider::SlackProvider::THREAD] = ts
+    end
+    def slack_thread_id
+      self.custom_fields[DiscourseChat::Provider::SlackProvider::THREAD]
+    end
+  end
+
   def self.excerpt(post, max_length = SiteSetting.chat_integration_slack_excerpt_length)
     doc = Nokogiri::HTML.fragment(post.excerpt(max_length,
       remap_emoji: true,
@@ -18,7 +31,7 @@ module DiscourseChat::Provider::SlackProvider
     SlackMessageFormatter.format(doc.to_html)
   end
 
-  def self.slack_message(post, channel)
+  def self.slack_message(post, channel, filter)
     display_name = "@#{post.user.username}"
     full_name = post.user.name || ""
 
@@ -56,6 +69,10 @@ module DiscourseChat::Provider::SlackProvider
       attachments: []
     }
 
+    if filter == "thread" && thread_ts = topic.slack_thread_id
+      message[:thread_ts] = thread_ts if not thread_ts.nil?
+    end
+
     summary = {
       fallback: "#{topic.title} - #{display_name}",
       author_name: display_name,
@@ -79,11 +96,9 @@ module DiscourseChat::Provider::SlackProvider
 
     response = nil
     uri = ""
-    record = DiscourseChat.pstore_get("slack_topic_#{post.topic.id}_#{channel}")
 
-    data = {
-      token: SiteSetting.chat_integration_slack_access_token,
-    }
+    # <!--SLACK_CHANNEL_ID=#{@channel_id};SLACK_TS=#{@requested_thread_ts}-->
+    slack_thread_regex = /<!--SLACK_CHANNEL_ID=(\w+);SLACK_TS=([0-9]{10}.[0-9]{6})-->/
 
     req = Net::HTTP::Post.new(URI('https://slack.com/api/chat.postMessage'))
 
@@ -94,6 +109,12 @@ module DiscourseChat::Provider::SlackProvider
       channel: message[:channel].gsub('#', ''),
       attachments: message[:attachments].to_json
     }
+    if message.key?(:thread_ts)
+      data[:thread_ts] = message[:thread_ts]
+    elsif match = slack_thread_regex.match(post.raw)
+      post.topic.slack_thread_id = match.captures[1]
+      post.topic.save_custom_fields
+    end
 
     req.set_form_data(data)
 
@@ -114,6 +135,12 @@ module DiscourseChat::Provider::SlackProvider
       raise ::DiscourseChat::ProviderError.new info: { error_key: error_key, request: uri, response_code: response.code, response_body: response.body }
     end
 
+    ts = json["ts"]
+    if !ts.nil? && post.topic.slack_thread_id.nil?
+      post.topic.slack_thread_id = ts
+      post.topic.save_custom_fields
+    end
+
     response
   end
 
@@ -137,9 +164,10 @@ module DiscourseChat::Provider::SlackProvider
 
   end
 
-  def self.trigger_notification(post, channel)
+  def self.trigger_notification(post, channel, rule)
     channel_id = channel.data['identifier']
-    message = slack_message(post, channel_id)
+    filter = rule.nil? ? "" : rule.filter
+    message = slack_message(post, channel_id, filter)
 
     if SiteSetting.chat_integration_slack_access_token.empty?
       self.send_via_webhook(message)

lib/discourse_chat/provider/slack/slack_transcript.rb

@@ -118,6 +118,10 @@ module DiscourseChat::Provider::SlackProvider
         post_content << "[#{username}]: #{url}\n"
       end
 
+      if not @requested_thread_ts.nil?
+        post_content << "<!--SLACK_CHANNEL_ID=#{@channel_id};SLACK_TS=#{@requested_thread_ts}-->"
+      end
+
       post_content
     end
 

lib/discourse_chat/provider/telegram/telegram_provider.rb

@@ -79,7 +79,7 @@ module DiscourseChat
 
       end
 
-      def self.trigger_notification(post, channel)
+      def self.trigger_notification(post, channel, rule)
         chat_id = channel.data['chat_id']
 
         message = {

lib/discourse_chat/provider/zulip/zulip_provider.rb

@@ -46,7 +46,7 @@ module DiscourseChat
         }
       end
 
-      def self.trigger_notification(post, channel)
+      def self.trigger_notification(post, channel, rule)
 
         stream = channel.data['stream']
         subject = channel.data['subject']

plugin.rb

@@ -11,6 +11,7 @@ enabled_site_setting :chat_integration_enabled
 register_asset "stylesheets/chat-integration-admin.scss"
 
 register_svg_icon "rocket" if respond_to?(:register_svg_icon)
+register_svg_icon "fa-arrow-circle-o-right" if respond_to?(:register_svg_icon)
 
 # Site setting validators must be loaded before initialize
 require_relative "lib/discourse_chat/provider/slack/slack_enabled_setting_validator"

spec/dummy_provider.rb

@@ -10,7 +10,7 @@ RSpec.shared_context "dummy provider" do
       @@sent_messages = []
       @@raise_exception = nil
 
-      def self.trigger_notification(post, channel)
+      def self.trigger_notification(post, channel, rule)
         if @@raise_exception
           raise @@raise_exception
         end
@@ -50,7 +50,7 @@ RSpec.shared_context "validated dummy provider" do
 
       @@sent_messages = []
 
-      def self.trigger_notification(post, channel)
+      def self.trigger_notification(post, channel, rule)
         @@sent_messages.push(post: post.id, channel: channel)
       end
 

spec/helpers/helper_spec.rb

@@ -32,7 +32,12 @@ RSpec.describe DiscourseChat::Manager do
         expect(rule.tags).to eq(nil)
       end
 
-        it 'should work with all three filter types' do
+        it 'should work with all four filter types' do
+          response = DiscourseChat::Helper.process_command(chan1, ['thread', category.slug])
+
+          rule = DiscourseChat::Rule.all.first
+          expect(rule.filter).to eq('thread')
+
           response = DiscourseChat::Helper.process_command(chan1, ['watch', category.slug])
 
           rule = DiscourseChat::Rule.all.first

spec/lib/discourse_chat/provider/discord/discord_provider_spec.rb

@@ -14,7 +14,7 @@ RSpec.describe DiscourseChat::Provider::DiscordProvider do
 
     it 'sends a webhook request' do
       stub1 = stub_request(:post, 'https://discordapp.com/api/webhooks/1234/abcd?wait=true').to_return(status: 200)
-      described_class.trigger_notification(post, chan1)
+      described_class.trigger_notification(post, chan1, nil)
       expect(stub1).to have_been_requested.once
     end
 
@@ -22,14 +22,14 @@ RSpec.describe DiscourseChat::Provider::DiscordProvider do
       stub1 = stub_request(:post, 'https://discordapp.com/api/webhooks/1234/abcd?wait=true')
         .with(body: hash_including(embeds: [hash_including(author: hash_including(url: /^https?:\/\//))]))
         .to_return(status: 200)
-      described_class.trigger_notification(post, chan1)
+      described_class.trigger_notification(post, chan1, nil)
       expect(stub1).to have_been_requested.once
     end
 
     it 'handles errors correctly' do
       stub1 = stub_request(:post, "https://discordapp.com/api/webhooks/1234/abcd?wait=true").to_return(status: 400)
       expect(stub1).to have_been_requested.times(0)
-      expect { described_class.trigger_notification(post, chan1) }.to raise_exception(::DiscourseChat::ProviderError)
+      expect { described_class.trigger_notification(post, chan1, nil) }.to raise_exception(::DiscourseChat::ProviderError)
       expect(stub1).to have_been_requested.once
     end
 

spec/lib/discourse_chat/provider/flowdock/flowdock_provider_spec.rb

@@ -14,14 +14,14 @@ RSpec.describe DiscourseChat::Provider::FlowdockProvider do
 
     it 'sends a request' do
       stub1 = stub_request(:post, "https://api.flowdock.com/messages").to_return(status: 200)
-      described_class.trigger_notification(post, chan1)
+      described_class.trigger_notification(post, chan1, nil)
       expect(stub1).to have_been_requested.once
     end
 
     it 'handles errors correctly' do
       stub1 = stub_request(:post, "https://api.flowdock.com/messages").to_return(status: 404, body: "{ \"error\": \"Not Found\"}")
       expect(stub1).to have_been_requested.times(0)
-      expect { described_class.trigger_notification(post, chan1) }.to raise_exception(::DiscourseChat::ProviderError)
+      expect { described_class.trigger_notification(post, chan1, nil) }.to raise_exception(::DiscourseChat::ProviderError)
       expect(stub1).to have_been_requested.once
     end
   end

spec/lib/discourse_chat/provider/gitter/gitter_provider_spec.rb

@@ -14,14 +14,14 @@ RSpec.describe DiscourseChat::Provider::GitterProvider do
 
     it 'sends a webhook request' do
       stub1 = stub_request(:post, chan1.data['webhook_url']).to_return(body: "OK")
-      described_class.trigger_notification(post, chan1)
+      described_class.trigger_notification(post, chan1, nil)
       expect(stub1).to have_been_requested.once
     end
 
     it 'handles errors correctly' do
       stub1 = stub_request(:post, chan1.data['webhook_url']).to_return(status: 404, body: "{ \"error\": \"Not Found\"}")
       expect(stub1).to have_been_requested.times(0)
-      expect { described_class.trigger_notification(post, chan1) }.to raise_exception(::DiscourseChat::ProviderError)
+      expect { described_class.trigger_notification(post, chan1, nil) }.to raise_exception(::DiscourseChat::ProviderError)
       expect(stub1).to have_been_requested.once
     end
   end

spec/lib/discourse_chat/provider/groupme/groupme_provider_spect.rb

@@ -15,14 +15,14 @@ RSpec.describe DiscourseChat::Provider::GroupmeProvider do
 
     it 'sends a request' do
       stub1 = stub_request(:post, "https://api.groupme.com/v3/bots/post").to_return(status: 200)
-      described_class.trigger_notification(post, chan1)
+      described_class.trigger_notification(post, chan1, nil)
       expect(stub1).to have_been_requested.once
     end
 
     it 'handles errors correctly' do
       stub1 = stub_request(:post, "https://api.groupme.com/v3/bots/post").to_return(status: 404, body: "{ \"error\": \"Not Found\"}")
       expect(stub1).to have_been_requested.times(0)
-      expect { described_class.trigger_notification(post, chan1) }.to raise_exception(::DiscourseChat::ProviderError)
+      expect { described_class.trigger_notification(post, chan1, nil) }.to raise_exception(::DiscourseChat::ProviderError)
       expect(stub1).to have_been_requested.once
     end
   end

spec/lib/discourse_chat/provider/matrix/matrix_provider_spec.rb

@@ -15,14 +15,14 @@ RSpec.describe DiscourseChat::Provider::MatrixProvider do
 
     it 'sends the message' do
       stub1 = stub_request(:put, %r{https://matrix.org/_matrix/client/r0/rooms/!blah:matrix.org/send/m.room.message/*}).to_return(status: 200)
-      described_class.trigger_notification(post, chan1)
+      described_class.trigger_notification(post, chan1, nil)
       expect(stub1).to have_been_requested.once
     end
 
     it 'handles errors correctly' do
       stub1 = stub_request(:put, %r{https://matrix.org/_matrix/client/r0/rooms/!blah:matrix.org/send/m.room.message/*}).to_return(status: 400, body: '{"errmsg":"M_UNKNOWN"}')
       expect(stub1).to have_been_requested.times(0)
-      expect { described_class.trigger_notification(post, chan1) }.to raise_exception(::DiscourseChat::ProviderError)
+      expect { described_class.trigger_notification(post, chan1, nil) }.to raise_exception(::DiscourseChat::ProviderError)
       expect(stub1).to have_been_requested.once
     end
 

spec/lib/discourse_chat/provider/mattermost/mattermost_provider_spec.rb

@@ -18,7 +18,7 @@ RSpec.describe DiscourseChat::Provider::MattermostProvider do
 
     it 'sends a webhook request' do
       stub1 = stub_request(:post, 'https://mattermost.blah/hook/abcd').to_return(status: 200)
-      described_class.trigger_notification(post, chan1)
+      described_class.trigger_notification(post, chan1, nil)
       expect(stub1).to have_been_requested.once
     end
 
@@ -40,7 +40,7 @@ RSpec.describe DiscourseChat::Provider::MattermostProvider do
     it 'handles errors correctly' do
       stub1 = stub_request(:post, "https://mattermost.blah/hook/abcd").to_return(status: 500, body: "error")
       expect(stub1).to have_been_requested.times(0)
-      expect { described_class.trigger_notification(post, chan1) }.to raise_exception(::DiscourseChat::ProviderError)
+      expect { described_class.trigger_notification(post, chan1, nil) }.to raise_exception(::DiscourseChat::ProviderError)
       expect(stub1).to have_been_requested.once
     end
 

spec/lib/discourse_chat/provider/rocketchat/rocketchat_provider_spec.rb

@@ -15,14 +15,14 @@ RSpec.describe DiscourseChat::Provider::RocketchatProvider do
 
     it 'sends a webhook request' do
       stub1 = stub_request(:post, 'https://example.com/abcd').to_return(body: "{\"success\":true}")
-      described_class.trigger_notification(post, chan1)
+      described_class.trigger_notification(post, chan1, nil)
       expect(stub1).to have_been_requested.once
     end
 
     it 'handles errors correctly' do
       stub1 = stub_request(:post, 'https://example.com/abcd').to_return(status: 400, body: "{}")
       expect(stub1).to have_been_requested.times(0)
-      expect { described_class.trigger_notification(post, chan1) }.to raise_exception(::DiscourseChat::ProviderError)
+      expect { described_class.trigger_notification(post, chan1, nil) }.to raise_exception(::DiscourseChat::ProviderError)
       expect(stub1).to have_been_requested.once
     end
 

spec/lib/discourse_chat/provider/slack/slack_provider_spec.rb

@@ -75,36 +75,65 @@ RSpec.describe DiscourseChat::Provider::SlackProvider do
 
     it 'sends a webhook request' do
       stub1 = stub_request(:post, SiteSetting.chat_integration_slack_outbound_webhook_url).to_return(body: "success")
-      described_class.trigger_notification(post, chan1)
+      described_class.trigger_notification(post, chan1, nil)
       expect(stub1).to have_been_requested.once
     end
 
     it 'handles errors correctly' do
       stub1 = stub_request(:post, SiteSetting.chat_integration_slack_outbound_webhook_url).to_return(status: 400, body: "error")
       expect(stub1).to have_been_requested.times(0)
-      expect { described_class.trigger_notification(post, chan1) }.to raise_exception(::DiscourseChat::ProviderError)
+      expect { described_class.trigger_notification(post, chan1, nil) }.to raise_exception(::DiscourseChat::ProviderError)
       expect(stub1).to have_been_requested.once
     end
 
     describe 'with api token' do
       before do
         SiteSetting.chat_integration_slack_access_token = "magic"
+        @ts = "#{Time.now.to_i}.012345"
         @stub1 = stub_request(:post, SiteSetting.chat_integration_slack_outbound_webhook_url).to_return(body: "success")
-        @stub2 = stub_request(:post, %r{https://slack.com/api/chat.postMessage}).to_return(body: "{\"ok\":true, \"ts\": \"#{Time.now.to_i}.012345\", \"message\": {\"attachments\": [], \"username\":\"blah\", \"text\":\"blah2\"} }", headers: { 'Content-Type' => 'application/json' })
-        @stub3 = stub_request(:post, %r{https://slack.com/api/chat.update}).to_return(body: '{"ok":true, "ts": "some_message_id"}', headers: { 'Content-Type' => 'application/json' })
+        @thread_stub = stub_request(:post, %r{https://slack.com/api/chat.postMessage}).with(body: hash_including("thread_ts" => @ts)).to_return(body: "{\"ok\":true, \"ts\": \"12345.67890\", \"message\": {\"attachments\": [], \"username\":\"blah\", \"text\":\"blah2\"} }", headers: { 'Content-Type' => 'application/json' })
+        @stub2 = stub_request(:post, %r{https://slack.com/api/chat.postMessage}).to_return(body: "{\"ok\":true, \"ts\": \"#{@ts}\", \"message\": {\"attachments\": [], \"username\":\"blah\", \"text\":\"blah2\"} }", headers: { 'Content-Type' => 'application/json' })
+        @channel = DiscourseChat::Channel.create(provider: 'dummy')
       end
 
       it 'sends an api request' do
         expect(@stub2).to have_been_requested.times(0)
+        expect(@thread_stub).to have_been_requested.times(0)
 
-        described_class.trigger_notification(post, chan1)
+        described_class.trigger_notification(post, chan1, nil)
         expect(@stub1).to have_been_requested.times(0)
         expect(@stub2).to have_been_requested.once
+        expect(post.topic.slack_thread_id).to eq(@ts)
+        expect(@thread_stub).to have_been_requested.times(0)
+      end
+
+      it 'sends thread id for thread' do
+        expect(@thread_stub).to have_been_requested.times(0)
+
+        rule = DiscourseChat::Rule.create(channel: @channel, filter: "thread")
+        post.topic.slack_thread_id = @ts
+
+        described_class.trigger_notification(post, chan1, rule)
+        expect(@thread_stub).to have_been_requested.once
+      end
+
+      it 'recognizes slack thread ts in comment' do
+        post.update!(cooked: "cooked", raw: <<~RAW
+             My fingers are typing words that improve `raw_quality`
+             <!--SLACK_CHANNEL_ID=UIGNOREFORNOW;SLACK_TS=1501801629.052212-->
+        RAW
+        )
+
+        rule = DiscourseChat::Rule.create(channel: @channel, filter: "thread")
+        post.topic.slack_thread_id = nil
+
+        described_class.trigger_notification(post, chan1, rule)
+        expect(post.topic.slack_thread_id).to eq('1501801629.052212')
       end
 
       it 'handles errors correctly' do
         @stub2 = stub_request(:post, %r{https://slack.com/api/chat.postMessage}).to_return(body: "{\"ok\":false }", headers: { 'Content-Type' => 'application/json' })
-        expect { described_class.trigger_notification(post, chan1) }.to raise_exception(::DiscourseChat::ProviderError)
+        expect { described_class.trigger_notification(post, chan1, nil) }.to raise_exception(::DiscourseChat::ProviderError)
         expect(@stub2).to have_been_requested.once
       end