Delete all posts when the blog expires

Closes #4

This is the actual meat of the application.

See https://github.com/collectiveidea/delayed_job/

app/assets/javascripts/application.js

@@ -18,7 +18,7 @@
 //= require_tree .
 
 function getTimeRemaining(endtime){
-  var t = Date.parse(endtime) - Date.parse(new Date());
+  var t = Date.parse(endtime) - (new Date()).getTime();
   var seconds = Math.floor( (t/1000) % 60 );
   var minutes = Math.floor( (t/1000/60) % 60 );
   var hours = Math.floor( (t/(1000*60*60)) % 24 );

app/controllers/posts_controller.rb

@@ -1,4 +1,5 @@
 class PostsController < ApplicationController
+  include ApplicationHelper
   before_action :set_post, only: [:show, :edit, :update, :destroy]
 
   http_basic_authenticate_with(
@@ -30,6 +31,7 @@ def create
     @post = Post.new(post_params)
 
     if @post.save
+      SelfDestruct.new.delay(run_at: expiration_time).attempt
       redirect_to @post, notice: "Post was successfully created."
     else
       render :new

app/helpers/application_helper.rb

@@ -1,11 +1,15 @@
+# frozen_string_literal: true
+
 module ApplicationHelper
+  GRACE_PERIOD = 1.week.freeze
+
   def markdown(source)
     Redcarpet::Markdown.new(Redcarpet::Render::HTML).render(source).html_safe
   end
 
   def expiration_time
     if Post.any?
-      Post.order(created_at: :desc).first.created_at + 7.days
+      Post.order(created_at: :desc).first.created_at + GRACE_PERIOD
     else
       Time.current
     end

app/jobs/self_destruct.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class SelfDestruct
+  include ApplicationHelper
+
+  def attempt
+    if Time.current > expiration_time
+      Rails.logger.fatal "[Self Destruct] Time expired, deleting all posts!"
+      Post.destroy_all
+    else
+      Rails.logger.info "[Self Destruct] Time has not expired, cancelling self-destruct"
+    end
+  end
+end

spec/models/self_destruct_spec.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+describe SelfDestruct do
+  describe "#attempt" do
+    it "deletes all posts if it is after the expiration" do
+      grace_period = ApplicationHelper::GRACE_PERIOD
+      create(:post, created_at: (grace_period + 1.minute).ago)
+
+      expect { SelfDestruct.new.attempt }.to change(Post, :count).from(1).to(0)
+    end
+
+    it "does not delete anything if it is before the expiration" do
+      grace_period = ApplicationHelper::GRACE_PERIOD
+      create(:post, created_at: (grace_period + 1.minute).ago)
+      create(:post, created_at: (grace_period - 1.minute).ago)
+
+      expect { SelfDestruct.new.attempt }.not_to change(Post, :count).from(2)
+    end
+  end
+end