Rails Tutorial Chapter 3 Notes

It is a memorandum of Chapter 3.

environment

Rails 6.0.3 Ruby 2.6.3

table of contents

How to undo with 1 command operation 2 HTTP method 3 Empty methods behave differently in Rails 4 Decrypt default test 5 Routing Introduction of 6 minitest reporters 7 Introduced Guard test automation

1 How to restore by command operation

Occasional command operation failure. If you delete only the wrong file, the code inserted in another file will remain when that file is created, so the model or controller generated by the command must be deleted by the command as well.

#Controller creation
$ rails generate controller StaticPages home help

#Controller removed
$ rails destroy controller StaticPages home help

You can delete the model in the same way.

Next is migration

#Migration changes (updates)
$ rails db:migrate

#Revert migration to previous state
$ rails db:rollback

#Make the migration the initial state (VERSION)=I want to return to 0)
$ rails db:migrate VERSION=0

The VERSION number is set every time you do rails db: migrate, so you can replace it with another number.

2 HTTP method

HTTP (HyperText Transfer Protocol) has four basic operations: `GET` `` `POST PATCH DELETE```.

GET	POST	PATCH	Delete
Get the page	Create based on the value entered in the form	update	Delete

3 Empty method behavior

In Rails, even an empty method behaves differently

app/controllers/staticpages_controller.rb

class StaticPagesController < ApplicationController
  def home
  end
  .
  .
end

Even in this case, the StaticPagesController class inherits from the Rails class called ApplicationController, so when you access/static_pages/home, you'll see a view called home.html.erb.

4 Decrypt the default test

test/controllers/static_pages_controller_test.rb

require 'test_helper'

class StaticPagesControllerTest < ActionDispatch::IntegrationTest

  test "should get home" do
    get static_pages_home_url
    assert_response :success
    assert_select "title", "Home | Ruby on Rails Tutorial Sample App"
  end

  .
  .
end

Confirmation of this test is a method called "assertion", which gets an action and confirms that it works normally.

The above test flow is 1, GET request for home action (display page) 2, Response becomes successful (200) 3, The character string described in the ```