discourse/plugins/discourse-github/app/lib/github_permalinks.rb

# frozen_string_literal: true

module GithubPermalinks
  def self.replace_github_non_permalinks(post)
    # replaces github non-permalinks with permalinks containing a specific commit id
    regex = %r{https?://github\.com/[^/]+/[^/\s]+/blob/[^\s]+}i

    # don't replace urls in posts that are more than 1h old
    return if ((Time.zone.now - post.created_at) / 60).round > 60

    # only run the job when post is changed by a user and it contains a github url
    return if (post.last_editor_id && post.last_editor_id <= 0) || !post.raw.match(regex)

    # make sure no other job is scheduled
    Jobs.cancel_scheduled_job(:replace_github_non_permalinks, post_id: post.id)

    # schedule the job
    Jobs.enqueue_in(
      (SiteSetting.editing_grace_period + 1).seconds.to_i,
      :replace_github_non_permalinks,
      post_id: post.id,
      bypass_bump: false,
    )
  end
end