miss

app/assets/stylesheets/scaffolds.scss

+body {
+  background-color: #fff;
+  color: #333;
+  margin: 33px; }
+
+body, p, ol, ul, td {
+  font-family: verdana, arial, helvetica, sans-serif;
+  font-size: 13px;
+  line-height: 18px; }
+
+pre {
+  background-color: #eee;
+  padding: 10px;
+  font-size: 11px; }
+
+a {
+  color: #000; }
+
+a:visited {
+  color: #666; }
+
+a:hover {
+  color: #fff;
+  background-color: #000; }
+
+th {
+  padding-bottom: 5px; }
+
+td {
+  padding: 0 5px 7px; }
+
+div.field,
+div.actions {
+  margin-bottom: 10px; }
+
+#notice {
+  color: green; }
+
+.field_with_errors {
+  padding: 2px;
+  background-color: red;
+  display: table; }
+
+#error_explanation {
+  width: 450px;
+  border: 2px solid red;
+  padding: 7px 7px 0;
+  margin-bottom: 20px;
+  background-color: #f0f0f0; }
+
+#error_explanation h2 {
+  text-align: left;
+  font-weight: bold;
+  padding: 5px 5px 5px 15px;
+  font-size: 12px;
+  margin: -7px -7px 0;
+  background-color: #c00;
+  color: #fff; }
+
+#error_explanation ul li {
+  font-size: 12px;
+  list-style: square; }
+
+label {
+  display: block; }

app/assets/stylesheets/users.scss

+// Place all the styles related to the Users controller here.
+// They will automatically be included in application.css.
+// You can use Sass (SCSS) here: https://sass-lang.com/

app/controllers/users_controller.rb

+class UsersController < ApplicationController
+  before_action :set_user, only: [:show, :edit, :update, :destroy]
+
+  # GET /users
+  # GET /users.json
+  def index
+    @users = User.all
+  end
+
+  # GET /users/1
+  # GET /users/1.json
+  def show
+  end
+
+  # GET /users/new
+  def new
+    @user = User.new
+  end
+
+  # GET /users/1/edit
+  def edit
+  end
+
+  # POST /users
+  # POST /users.json
+  def create
+    @user = User.new(user_params)
+
+    respond_to do |format|
+      if @user.save
+        format.html { redirect_to @user, notice: 'User was successfully created.' }
+        format.json { render :show, status: :created, location: @user }
+      else
+        format.html { render :new }
+        format.json { render json: @user.errors, status: :unprocessable_entity }
+      end
+    end
+  end
+
+  # PATCH/PUT /users/1
+  # PATCH/PUT /users/1.json
+  def update
+    respond_to do |format|
+      if @user.update(user_params)
+        format.html { redirect_to @user, notice: 'User was successfully updated.' }
+        format.json { render :show, status: :ok, location: @user }
+      else
+        format.html { render :edit }
+        format.json { render json: @user.errors, status: :unprocessable_entity }
+      end
+    end
+  end
+
+  # DELETE /users/1
+  # DELETE /users/1.json
+  def destroy
+    @user.destroy
+    respond_to do |format|
+      format.html { redirect_to users_url, notice: 'User was successfully destroyed.' }
+      format.json { head :no_content }
+    end
+  end
+
+  private
+    # Use callbacks to share common setup or constraints between actions.
+    def set_user
+      @user = User.find(params[:id])
+    end
+
+    # Only allow a list of trusted parameters through.
+    def user_params
+      params.require(:user).permit(:name, :email)
+    end
+end

app/helpers/users_helper.rb

+module UsersHelper
+end

app/models/user.rb

+class User < ApplicationRecord
+end

app/views/users/_form.html.erb

+<%= form_with(model: user) do |form| %>
+  <% if user.errors.any? %>
+    <div id="error_explanation">
+      <h2><%= pluralize(user.errors.count, "error") %> prohibited this user from being saved:</h2>
+
+      <ul>
+        <% user.errors.each do |error| %>
+          <li><%= error.full_message %></li>
+        <% end %>
+      </ul>
+    </div>
+  <% end %>
+
+  <div class="field">
+    <%= form.label :name %>
+    <%= form.text_field :name %>
+  </div>
+
+  <div class="field">
+    <%= form.label :email %>
+    <%= form.text_field :email %>
+  </div>
+
+  <div class="actions">
+    <%= form.submit %>
+  </div>
+<% end %>

app/views/users/_user.json.jbuilder

+json.extract! user, :id, :name, :email, :created_at, :updated_at
+json.url user_url(user, format: :json)

app/views/users/edit.html.erb

+<h1>Editing User</h1>
+
+<%= render 'form', user: @user %>
+
+<%= link_to 'Show', @user %> |
+<%= link_to 'Back', users_path %>

app/views/users/index.html.erb

+<p id="notice"><%= notice %></p>
+
+<h1>Users</h1>
+
+<table>
+  <thead>
+    <tr>
+      <th>Name</th>
+      <th>Email</th>
+      <th colspan="3"></th>
+    </tr>
+  </thead>
+
+  <tbody>
+    <% @users.each do |user| %>
+      <tr>
+        <td><%= user.name %></td>
+        <td><%= user.email %></td>
+        <td><%= link_to 'Show', user %></td>
+        <td><%= link_to 'Edit', edit_user_path(user) %></td>
+        <td><%= link_to 'Destroy', user, method: :delete, data: { confirm: 'Are you sure?' } %></td>
+      </tr>
+    <% end %>
+  </tbody>
+</table>
+
+<br>
+
+<%= link_to 'New User', new_user_path %>

app/views/users/index.json.jbuilder

+json.array! @users, partial: "users/user", as: :user

app/views/users/new.html.erb

+<h1>New User</h1>
+
+<%= render 'form', user: @user %>
+
+<%= link_to 'Back', users_path %>

app/views/users/show.html.erb

+<p id="notice"><%= notice %></p>
+
+<p>
+  <strong>Name:</strong>
+  <%= @user.name %>
+</p>
+
+<p>
+  <strong>Email:</strong>
+  <%= @user.email %>
+</p>
+
+<%= link_to 'Edit', edit_user_path(@user) %> |
+<%= link_to 'Back', users_path %>

app/views/users/show.json.jbuilder

+json.partial! "users/user", user: @user

config/environments/development.rb

@@ -73,4 +73,5 @@ Rails.application.configure do
 
   # Uncomment if you wish to allow Action Cable access from any origin.
   # config.action_cable.disable_request_forgery_protection = true
+  config.hosts.clear
 end

config/environments/production.rb

@@ -28,7 +28,7 @@ Rails.application.configure do
   # config.assets.css_compressor = :sass
 
   # Do not fallback to assets pipeline if a precompiled asset is missed.
-  config.assets.compile = false
+  config.assets.compile = true
 
   # Enable serving of images, stylesheets, and JavaScripts from an asset server.
   # config.asset_host = 'http://assets.example.com'

config/routes.rb

 Rails.application.routes.draw do
+  resources :users
   root 'application#hello'
   # For details on the DSL available within this file, see https://guides.rubyonrails.org/routing.html
 end

db/migrate/20210601082234_create_users.rb

+class CreateUsers < ActiveRecord::Migration[6.1]
+  def change
+    create_table :users do |t|
+      t.string :name
+      t.string :email
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

+# This file is auto-generated from the current state of the database. Instead
+# of editing this file, please use the migrations feature of Active Record to
+# incrementally modify your database, and then regenerate this schema definition.
+#
+# This file is the source Rails uses to define your schema when running `bin/rails
+# db:schema:load`. When creating a new database, `bin/rails db:schema:load` tends to
+# be faster and is potentially less error prone than running all of your
+# migrations from scratch. Old migrations may fail to apply correctly if those
+# migrations use external dependencies or application code.
+#
+# It's strongly recommended that you check this file into your version control system.
+
+ActiveRecord::Schema.define(version: 2021_06_01_082234) do
+
+  create_table "users", force: :cascade do |t|
+    t.string "name"
+    t.string "email"
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+  end
+
+end

test/controllers/users_controller_test.rb

+require "test_helper"
+
+class UsersControllerTest < ActionDispatch::IntegrationTest
+  setup do
+    @user = users(:one)
+  end
+
+  test "should get index" do
+    get users_url
+    assert_response :success
+  end
+
+  test "should get new" do
+    get new_user_url
+    assert_response :success
+  end
+
+  test "should create user" do
+    assert_difference('User.count') do
+      post users_url, params: { user: { email: @user.email, name: @user.name } }
+    end
+
+    assert_redirected_to user_url(User.last)
+  end
+
+  test "should show user" do
+    get user_url(@user)
+    assert_response :success
+  end
+
+  test "should get edit" do
+    get edit_user_url(@user)
+    assert_response :success
+  end
+
+  test "should update user" do
+    patch user_url(@user), params: { user: { email: @user.email, name: @user.name } }
+    assert_redirected_to user_url(@user)
+  end
+
+  test "should destroy user" do
+    assert_difference('User.count', -1) do
+      delete user_url(@user)
+    end
+
+    assert_redirected_to users_url
+  end
+end

test/fixtures/users.yml

+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+one:
+  name: MyString
+  email: MyString
+
+two:
+  name: MyString
+  email: MyString

test/models/user_test.rb

+require "test_helper"
+
+class UserTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end

test/system/users_test.rb

+require "application_system_test_case"
+
+class UsersTest < ApplicationSystemTestCase
+  setup do
+    @user = users(:one)
+  end
+
+  test "visiting the index" do
+    visit users_url
+    assert_selector "h1", text: "Users"
+  end
+
+  test "creating a User" do
+    visit users_url
+    click_on "New User"
+
+    fill_in "Email", with: @user.email
+    fill_in "Name", with: @user.name
+    click_on "Create User"
+
+    assert_text "User was successfully created"
+    click_on "Back"
+  end
+
+  test "updating a User" do
+    visit users_url
+    click_on "Edit", match: :first
+
+    fill_in "Email", with: @user.email
+    fill_in "Name", with: @user.name
+    click_on "Update User"
+
+    assert_text "User was successfully updated"
+    click_on "Back"
+  end
+
+  test "destroying a User" do
+    visit users_url
+    page.accept_confirm do
+      click_on "Destroy", match: :first
+    end
+
+    assert_text "User was successfully destroyed"
+  end
+end