Added validations to Category model and validation tests

app/controllers/categories_controller.rb

@@ -1,2 +1,45 @@
 class CategoriesController < ApplicationController
+  def index
+    @categories = Category.all
+  end
+
+  def show
+    @category = Category.find_by(id: params[:id])
+    if @category.nil?
+      head :not_found
+      return
+    end
+  end
+
+  def new
+    @category = Category.new
+  end
+
+  def create
+    @category = Category.new( category_params )
+    if @category.save
+      redirect_to category_path(@category.id)
+    else
+      render new_category_path
+    end
+  end
+
+  def edit
+    @category = Category.find_by(id: params[:id] )
+  end
+
+  def update
+    @category = Category.find_by(id: params[:id] )
+    if @category.update( category_params )
+      redirect_to category_path(@category.id)
+    else
+      render new_category_path
+    end
+  end
+
+  private             
+
+  def category_params
+    return params.require(:category).permit(:name)
+  end
 end

app/models/category.rb

@@ -1,3 +1,5 @@
 class Category < ApplicationRecord
   has_and_belongs_to_many :products
+
+  validates :name, presence: true, uniqueness: true
 end

config/routes.rb

@@ -8,4 +8,5 @@
   delete "/logout", to: "users#destroy", as: "logout"
 
   resources :products, except: :destroy
+  resources :categories, except: :destroy
 end

test/controllers/categories_controller_test.rb

@@ -1,7 +1,44 @@
 require "test_helper"
 
 describe CategoriesController do
-  # it "does a thing" do
-  #   value(1+1).must_equal 2
-  # end
+  describe "index action" do
+    it "gives back a successful response" do
+      get categories_path
+
+      must_respond_with :success
+    end
+  end
+
+  describe 'show action' do
+    it 'responds with a success when id given exists' do
+
+      get category_path(categories(:valid_category).id)
+
+      must_respond_with :success
+
+    end
+
+    it 'responds with a not_found when id given does not exist' do
+
+      get category_path("-500")
+
+      must_respond_with :not_found
+    end
+  end
+
+  describe "create" do
+    it 'creates a new category successfully and redirects the user to the category page' do
+      category_hash = {
+        category: {
+          name: "New Category"
+        }
+      }
+
+      expect {
+        post categories_path, params: category_hash
+      }.must_differ 'Category.count', 1
+
+      must_redirect_to category_path(Category.find_by(name: "New Category"))
+    end
+  end
 end

test/fixtures/categories.yml

@@ -0,0 +1,5 @@
+valid_category:
+  name: ExpensiveItems
+
+valid_category2:
+  name: EvenPricierItems

test/models/category_test.rb

@@ -1,7 +1,29 @@
 require "test_helper"
 
 describe Category do
-  # it "does a thing" do
-  #   value(1+1).must_equal 2
-  # end
+  describe "validations" do
+    it "can be valid" do
+      is_valid = categories(:valid_category).valid?
+
+      assert( is_valid )
+    end
+
+    it "is invalid if there is no name" do
+      invalid_category = categories(:valid_category)
+      invalid_category.name = ""
+
+      is_valid = invalid_category.valid?
+
+      refute( is_valid )
+    end
+
+    it "gives an error message if the name given is not unique" do
+      invalid_category = categories(:valid_category2)
+      invalid_category.name = "ExpensiveItems"
+
+      is_valid = invalid_category.valid?
+
+      refute( is_valid )
+    end
+  end
 end