shkrt

http://stackoverflow.com/questions/22667401/postgres-json-data-type-rails-query
http://stackoverflow.com/questions/40702813/query-on-postgres-json-array-field-in-rails

#payload: [{"kind"=>"person"}]
Segment.where("payload @> ?", [{kind: "person"}].to_json)

#data: {"interest"=>["music", "movies", "programming"]}
Segment.where("data @> ?",  {"interest": ["music", "movies", "programming"]}.to_json)
Segment.where("data #>> '{interest, 1}' = 'movies' ")
Segment.where("jsonb_array_length(data->'interest') > 1")

shkrt

Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

Tables

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

Table alias

shkrt

Ruby Deep Dive - Table Of Contents

• Using Pry to Learn Ruby
  • The Power of Pry
  • Where did this method come from?
  • Debugging using Pry
• Understanding Exceptions
  • What are Exceptions and Why They Happen
  • Understanding Stack Traces
• Using Exceptions

shkrt

def match_host(issue_url)
  Matchers::GitHost.(issue_url) do |m|
    m.success(:github) { |issue_data| Services::GithubIssueRequester.(issue_data) }
    m.success(:gitlab) { |issue_data| Services::GitlabIssueRequester.(issue_data) }
    m.failure do
      error('invalid url')
      INVALID_URL_ERROR
    end
  end
end

shkrt

def match_host(issue_url)
  Container['matchers.git_host'].(issue_url) do |m|
    m.success(:github) { |issue_data| Container['services.github_issue_requester'].(issue_data) }
    m.success(:gitlab) { |issue_data| Container['services.gitlab_issue_requester'].(issue_data) }
    m.failure do
      error('invalid url')
      INVALID_URL_ERROR
    end
  end
end

shkrt

This temporary workaround is helpful, when test-kitchen is unable to connect to centos vm box via ssh with following error messages:

Waiting for SSH service on 127.0.0.1:2222, retrying in 3 seconds
Waiting for SSH service on 127.0.0.1:2222, retrying in 3 seconds
Waiting for SSH service on 127.0.0.1:2222, retrying in 3 seconds
Waiting for SSH service on 127.0.0.1:2222, retrying in 3 seconds

For kitchen create to work properly, one should create Vagrantfile.rb (extension is mandatory here) anywhere, and specify the path to this file in .kitchen.yml. The only content of this custom Vagrantfile is insert_key setting, because it's not being parsed properly by test-kitchen, when provided in .kitchen.yml.