FEATURE: Add new EnsureConsistency scheduled job

Add a new job that is scheduled twice daily to ensure the consistency of the calendar topic.

In some rare cases, like when a post is moved, the calendar is not properly updated.

Since reacting to a post being moved is hard (we don't have the information of the previous topics),
this job will ensure that the events of each posts in the calendar topic are up to date.

jobs/scheduled/ensure_consistency.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module Jobs
+  class ::DiscourseCalendar::EnsureConsistency < Jobs::Scheduled
+    every 12.hours
+
+    PLUGIN_NAME ||= "calendar"
+
+    def execute(args)
+      return unless SiteSetting.calendar_enabled
+      return unless topic_id = SiteSetting.holiday_calendar_topic_id
+      return unless op = Post.find_by(topic_id: topic_id, post_number: 1)
+      return unless op.calendar_details.present?
+
+      posts = Post
+        .where(topic_id: topic_id, post_number: op.calendar_details.keys)
+        .where("raw NOT LIKE '%[date%'")
+
+      posts.find_each do |post|
+        DistributedMutex.synchronize("#{PLUGIN_NAME}-#{post.id}") do
+          DiscourseCalendar::EventUpdater.update(post)
+        end
+      end
+    end
+  end
+end

plugin.rb

@@ -13,8 +13,8 @@ enabled_site_setting :calendar_enabled
 register_asset "stylesheets/vendor/fullcalendar.min.css"
 register_asset "stylesheets/common/discourse-calendar.scss"
 
-PLUGIN_NAME ||= "calendar".freeze
-DATA_PREFIX ||= "data-calendar-".freeze
+PLUGIN_NAME ||= "calendar"
+DATA_PREFIX ||= "data-calendar-"
 
 REGION_TO_EMOJI_FLAG ||= {
   "ar" => "argentina",
@@ -63,6 +63,7 @@ after_initialize do
     "../jobs/scheduled/ensure_expired_event_destruction.rb",
     "../jobs/scheduled/update_holiday_usernames.rb",
     "../jobs/scheduled/check_next_regional_holidays.rb",
+    "../jobs/scheduled/ensure_consistency.rb",
   ].each { |path| load File.expand_path(path, __FILE__) }
 
   register_post_custom_field_type(DiscourseCalendar::CALENDAR_DETAILS_CUSTOM_FIELD, :json)

spec/jobs/ensure_consistency_spec.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+describe DiscourseCalendar::EnsureConsistency do
+  before { SiteSetting.calendar_enabled = true }
+
+  it "works" do
+    op = create_post(raw: "[calendar]\n[/calendar]")
+
+    SiteSetting.holiday_calendar_topic_id = op.topic_id
+
+    post = create_post(raw: "Some Event [date=2019-09-10]", topic: op.topic)
+    CookedPostProcessor.new(post).post_process
+
+    op.reload
+    expect(op.calendar_details[post.post_number.to_s]).to be_present
+
+    DiscourseCalendar::EnsureConsistency.new.execute(nil)
+
+    op.reload
+    expect(op.calendar_details[post.post_number.to_s]).to be_present
+
+    PostMover
+      .new(op.topic, Discourse.system_user, [post.id])
+      .to_new_topic("A topic with some dates in it")
+
+    DiscourseCalendar::EnsureConsistency.new.execute(nil)
+
+    op.reload
+    expect(op.calendar_details).to eq({})
+  end
+end

spec/lib/event_updater_spec.rb

@@ -3,9 +3,7 @@
 require 'rails_helper'
 
 describe DiscourseCalendar::EventUpdater do
-  before do
-    SiteSetting.calendar_enabled = true
-  end
+  before { SiteSetting.calendar_enabled = true }
 
   it "will correctly update the associated first post calendar details" do
     op = create_post(raw: "[calendar]\n[/calendar]")