fernandes

# Chapter 2: Designing Classes with Single Responsability
Single Responsability
* Ask Each Method: 'Class whats your :method?'
* Hide Instance Variables
* Hide Data Structures
* Extract Extra Responsability From Methods

Dependencies
* Must known no Constant
* Must _not_ call methods on other objects (constants)

zulhfreelancer

It's important to note that running this reset will drop any existing data you have in the application

How to reset PG Database on Heroku?

• Step 1: heroku restart
• Step 2: heroku pg:reset DATABASE (no need to change the DATABASE)
• Step 3: heroku run rake db:migrate
• Step 4: heroku run rake db:seed (if you have seed)

One liner

eliotsykes

require 'rails_helper'

RSpec.describe TodosController, :type => :controller do

  describe "GET #index" do
  #describe "POST #create" do
  #describe "GET #show" do
  #describe "PATCH #update" do (or PUT #update)
  #describe "DELETE #destroy" do
  #describe "GET #new" do

speric

Chapter 1 - Object Oriented Design

The purpose of design is to allow you to do design later, and it's primary goal is to reduce the cost of change.

SOLID Design:

• Single Responsibility Principle: a class should have only a single responsibility
• Open-Closed Principle: Software entities should be open for extension, but closed for modification (inherit instead of modifying existing classes).
• Liskov Substitution: Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.
• Interface Segregation: Many client-specific interfaces are better than one general-purpose interface.

justinweiss

# Call scopes directly from your URL params:
#
#     @products = Product.filter(params.slice(:status, :location, :starts_with))
module Filterable
  extend ActiveSupport::Concern

  module ClassMethods
    
    # Call the class methods with names based on the keys in <tt>filtering_params</tt>
    # with their associated values. For example, "{ status: 'delayed' }" would call 

them0nk

#Model 

@user.should have(1).error_on(:username) # Checks whether there is an error in username 
@user.errors[:username].should include("can't be blank")  # check for the error message 

#Rendering
response.should render_template(:index)

#Redirecting 
response.should redirect_to(movies_path)