Testing controller with RSpec - sample.

campaigns_controller_spec.rb

require 'spec_helper'

describe CampaignsController do
  let(:user){ create(:admin_user) }

  before(:each) do    
    sign_in user
  end

  describe "GET #index" do
    let!(:campaign){ create(:campaign) }

    it "renders the :index view" do
      get :index
      response.should render_template :index
    end

    it "populates an array of campaigns" do
      get :index
      assigns(:campaigns).should eq([campaign])
    end
  end

  describe "GET #show" do
    let(:campaign){ create(:campaign) }

    it "renders the :show view" do
      get :show, :id => campaign.id
      response.should render_template :show
    end

    it "assigns requested campaign to @campaign" do
      get :show, :id => campaign.id
      assigns(:campaign).should eq(campaign)
    end
  end

  describe "GET #new" do
    it "renders the :new view" do
      get :new
      response.should render_template :new
    end

    it "assigns new campaign to @campaign" do
      get :new
      assigns(:campaign).should be_new_record
    end
  end

  describe "POST #create" do
    context "with valid attributes" do
      it "creates a new campaign" do
        expect{
          post :create, :campaign => attributes_for(:campaign)
        }.to change{Campaign.count}.by(1)
      end

      it "redirects to campaigns listing" do
        post :create, :campaign => attributes_for(:campaign)
        response.should redirect_to :campaigns
      end
    end

    context "with invalid attributes" do
      it "does not save the new campaign" do
        expect{
          post :create, :campaign => attributes_for(:invalid_campaign)
        }.to_not change{Campaign.count}
      end

      it "re-renders the new action" do
        post :create, :campaign => attributes_for(:invalid_campaign)
        response.should render_template :new
      end
    end
  end

  describe "GET #edit" do
    let(:campaign){ create(:campaign) }

    it "assigns requested campaign to @campaign" do
      get :edit, :id => campaign.id
      assigns(:campaign).should eq(campaign)
    end

    it "renders the :edit view" do
      get :edit, :id => campaign.id
      response.should render_template :edit
    end
  end

  describe "PUT #update" do
    let(:campaign){ create(:campaign) }

    context "with valid attributes" do
      it "locates the requested campaign" do
        put :update, :id => campaign.id, :campaign => attributes_for(:campaign)
        assigns(:campaign).should eq(campaign)
      end

      it "changes campaign attributes" do
        put :update, :id => campaign.id, :campaign => attributes_for(:campaign, :name => "Updated name")
        campaign.reload
        campaign.name.should eq("Updated name")
      end

      it "redirects to campaigns listing" do
        put :update, :id => campaign.id, :campaign => attributes_for(:campaign)
        response.should redirect_to :campaigns
      end
    end

    context "with invalid attributes" do
      it "locates the requested campaign" do
        put :update, :id => campaign.id, :campaign => attributes_for(:invalid_campaign)
        assigns(:campaign).should eq(campaign)
      end

      it "does not change campaign's attributes" do
        put :update, :id => campaign.id, :campaign => attributes_for(:campaign, :name => "")
        campaign.reload
        campaign.name.should eq("MyCampaign")
        campaign.name.should_not eq("Updated name")
      end

      it "re-renders the edit action" do
        put :update, :id => campaign.id, :campaign => attributes_for(:invalid_campaign)
        response.should render_template :edit
      end
    end
  end

  describe "DELETE #destroy" do
    let!(:campaign){ create(:campaign) }

    it "deletes the campaign" do
      expect{
        delete :destroy, :id => campaign.id
      }.to change{Campaign.count}.by(-1)
    end

    it "redirects campaigns listing" do
      delete :destroy, :id => campaign.id
      response.should redirect_to :campaigns
    end    
  end
end