Find discrepancies between campaigns (local ads) and remote ads.

We publish our jobs to different marketing sources. To keep track of where the particular job is published, we create Campaign entity in database. Campaigns are periodically synchronized with 3rd party Ad Service.

Campaign properties:

• id
• job_id
• status: one of [active, paused, deleted]
• external_reference: corresponds to Ad’s ‘reference’
• ad_description: text description of an Ad

Due to various types of failures (Ad Service unavailability, errors in campaign details etc.) local Campaigns can fall out of sync with Ad Service. So we need a way to detect discrepancies between local and remote state.

• Just for sake of simplicity, No DB used, but its loading data from a CSV file from db folder here.
• I have created various classes to follow the OOPs concept. CampaignAdsDiscrepancies::DiscrepanciesServices::DiscrepanciesDetector class is a high level class which is responsible to test overall functionality. Internally, this class calls all other classes and objects and return you the final result. CampaignAdsDiscrepancies::DiscrepanciesServices::DiscrepanciesDetector is only for better clarity and understanding.
• Not handling all kinds of external API errors.

[]

[
  {
    :remote_reference => "2",
    :discrepancies => [
      {
        "status" => {
          :remote => "disabled",
          :local => "paused"
        }
      }
    ]
  },
  {
    :remote_reference => "3",
    :discrepancies => [
      {
        "status" => {
          :remote => "enabled",
          :local => "deleted"
        },
        "description" => {
          :remote => "Description for campaign 13",
          :local => "Description for campaign 14"
        }
      }
    ]
  }
]

Run bundle exec rspec spec from command line.

Run bundle exec rake console to load entire application in IRB console. In IRB console, run

CampaignAdsDiscrepancies::DiscrepanciesServices::DiscrepanciesDetector.call

It will provide you all discrepancies found.