Section 4.4.2: Redirect the users back to the projects page if they try going to a project that does not exist

Author: Ryan Bigg

ticketee/app/controllers/projects_controller.rb

@@ -1,4 +1,8 @@
 class ProjectsController < ApplicationController
+  before_action :set_project, only: [:show,
+                                     :edit,
+                                     :update,
+                                     :destroy]
   def index
     @projects = Project.all
   end
@@ -19,17 +23,7 @@ def create
     end
   end
 
-  def show
-    @project = Project.find(params[:id])
-  end
-
-  def edit
-    @project = Project.find(params[:id])
-  end
-
   def update
-    @project = Project.find(params[:id])
-
     if @project.update(project_params)
       flash[:notice] = "Project has been updated."
       redirect_to @project
@@ -40,7 +34,6 @@ def update
   end
 
   def destroy
-    @project = Project.find(params[:id])
     @project.destroy
 
     flash[:notice] = "Project has been destroyed."
@@ -50,6 +43,15 @@ def destroy
 
   private
 
+  def set_project
+    @project = Project.find(params[:id])
+  rescue ActiveRecord::RecordNotFound
+    flash[:alert] = "The project you were looking" +
+                    " for could not be found."
+
+    redirect_to projects_path
+  end
+
   def project_params
     params.require(:project).permit(:name, :description)
   end

ticketee/spec/controllers/projects_controller_spec.rb

@@ -1,5 +1,12 @@
 require 'rails_helper'
 
 RSpec.describe ProjectsController, :type => :controller do
+  it "displays an error for a missing project" do
+    get :show, id: "not-here"
 
+    expect(response).to redirect_to(projects_path)
+    message = "The project you were looking for could not be found."
+
+    expect(flash[:alert]).to eql(message)
+  end
 end