lulalala

foo.save
foo.end_at.strftime('%H:%M:%S.%L')
"20:38:34.447"
foo.reload.end_at.strftime('%H:%M:%S.%L')
"20:38:34.000"

lulalala

      login(user)
      expect(page).to have_content("Logged in")
      visit foo_path

lulalala

book.errors.keys
[:title]
book.errors[:base].present?
false
book.errors.keys
[:title, :base]

# and someone does this
if book.errors.keys.include?(:base)
  boom!()

lulalala

#<Rack::BodyProxy: @body=
  #<Rack::BodyProxy: @body=
    #<Rack::BodyProxy: @body=
      #<Rack::BodyProxy: @body=
        #<Rack::BodyProxy: @body=
          #<Rack::BodyProxy: @body=
            #<Sprockets::StaticAsset

lulalala

      start_time = Time.now.to_f
      time_elapsed = lambda { ((Time.now.to_f - start_time) * 1000).to_i }
      logger.info "#{msg} 404 Not Found (#{time_elapsed.call}ms)"

lulalala

# This is generated using toy_scaffold,
# and is meant for learning purposes only.
# It aims for more clarity for beginners, therefore
# sacrifices some best practices and DRY principle.

class BooksController < ApplicationController
  # GET /books
  # View file is at app/views/books/index.html.erb
  def index
    @books = Book.all

lulalala

it do
  expect{
    @return_result = foo()
  }.to change(Foo, :count).from(1).to(0)
  expect(@return_result).to eq(true)
end

lulalala

  def foo(role)
    if !teacher?(role)

...

  def teacher?(role)
    role == :teacher

lulalala

  # insdie model
  def write_attribute(attr_name, value)
    super

    # Association assignment take effect after super
    case attr_name
    when 'admin_editing'
      pp "Inside write_attribute: #{self.admin_editing}"
    end
  end

lulalala

module Global
  def self.add_attribute(name)
    value = yield.freeze
    self.define_singleton_method(name) do
      value
    end
  end
end

Global.add_attribute(:topic_api_markdown_renderer){