Tests for ticket model

Change in error message of validation cause previously it was:
"Price currency Currency is different.."
`paid?` method returned true even when `ticket_purchases` is empty for
a given user.

app/models/ticket.rb

@@ -18,7 +18,7 @@ class Ticket < ActiveRecord::Base
   end
 
   def paid?(user)
-    ticket_purchases.where(user_id: user.id, paid: false).count == 0
+    ticket_purchases.find_by(user: user, paid: true).present?
   end
 
   def quantity_bought_by(user)
@@ -52,7 +52,7 @@ class Ticket < ActiveRecord::Base
 
   def tickets_of_conference_have_same_currency
     unless Ticket.where(conference_id: conference_id).all?{|t| t.price_currency == self.price_currency }
-      errors.add(:price_currency, 'Currency is different from the exist ticktes of this conference.')
+      errors.add(:price_currency, 'is different from the existing tickets of this conference.')
     end
   end
 end

spec/models/ticket_spec.rb

@@ -2,10 +2,10 @@ require 'spec_helper'
 
 describe Ticket do
   let(:conference) { create(:conference) }
-  let(:ticket) { create(:ticket, price: 50, conference: conference) }
+  let(:ticket) { create(:ticket, price: 50, price_currency: 'USD', conference: conference) }
   let(:user) { create(:user) }
 
-  describe 'validations' do
+  describe 'validation' do
     it 'has a valid factory' do
       expect(build(:ticket)).to be_valid
     end
@@ -33,6 +33,22 @@ describe Ticket do
     it 'is valid with a price_cents greater than zero' do
       should allow_value(1).for(:price_cents)
     end
+
+    it 'is not valid if tickets of conference do not have same currency' do
+      conflicting_currency_ticket = build(:ticket,
+                                          conference: ticket.conference,
+                                          price_currency: 'INR')
+      expected_error_message = 'Price currency is different from the existing tickets of this conference.'
+
+      expect(conflicting_currency_ticket).not_to be_valid
+      expect(conflicting_currency_ticket.errors.full_messages).to eq([expected_error_message])
+    end
+  end
+
+  describe 'association' do
+    it { should belong_to(:conference) }
+    it { should have_many(:ticket_purchases).dependent(:destroy) }
+    it { should have_many(:buyers).through(:ticket_purchases).source(:user) }
   end
 
   describe '#bought?' do
@@ -43,11 +59,29 @@ describe Ticket do
       expect(ticket.bought?(user)).to eq(true)
     end
 
-    it 'returns true if the user has bought this ticket' do
+    it 'returns false if the user has not bought this ticket' do
       expect(ticket.bought?(user)).to eq(false)
     end
   end
 
+  describe '#paid?' do
+    let!(:ticket_purchase) { create(:ticket_purchase, user: user, ticket: ticket) }
+
+    context 'user has paid' do
+      before { ticket_purchase.update_attributes(paid: true) }
+
+      it 'returns true' do
+        expect(ticket.paid?(user)).to eq(true)
+      end
+    end
+
+    context 'user has not paid' do
+      it 'returns false' do
+        expect(ticket.paid?(user)).to eq(false)
+      end
+    end
+  end
+
   describe '#quantity_bought_by' do
     it 'returns the correct value if the user has bought this ticket' do
       create(:ticket_purchase,
@@ -68,7 +102,7 @@ describe Ticket do
              user: user,
              ticket: ticket,
              quantity: 20)
-      expect(ticket.total_price(user)).to eq(Money.new(20 * ticket.price_cents, 'USD'))
+      expect(ticket.total_price(user)).to eq(Money.new(100000, 'USD'))
     end
 
     it 'returns zero if the user has not bought this ticket' do
@@ -76,17 +110,37 @@ describe Ticket do
     end
   end
 
-  describe 'self#total_price' do
-    it 'returns the correct value if the user has bought this ticket' do
-      create(:ticket_purchase,
-             user: user,
-             ticket: ticket,
-             quantity: 20)
-      expect(Ticket.total_price(conference, user)).to eq(Money.new(20 * ticket.price_cents, 'USD'))
-    end
+  describe 'self.total_price' do
+    let(:diversity_supporter_ticket) { create(:ticket, conference: conference, price: 500) }
 
-    it 'returns zero if the user has not bought this ticket' do
-      expect(Ticket.total_price(conference, user)).to eq(Money.new(0, 'USD'))
+    describe 'user has bought' do
+      context 'no tickets' do
+        it 'returns zero' do
+          expect(Ticket.total_price(conference, user)).to eq(Money.new(0, 'USD'))
+        end
+      end
+
+      context 'one type of ticket' do
+        before do
+          create(:ticket_purchase, ticket: ticket, user: user, quantity: 20)
+        end
+
+        it 'returns the correct total price' do
+          expect(Ticket.total_price(conference, user)).to eq(Money.new(100000, 'USD'))
+        end
+      end
+
+      context 'multiple types of tickets' do
+        before do
+          create(:ticket_purchase, ticket: ticket, user: user, quantity: 20)
+          create(:ticket_purchase, ticket: diversity_supporter_ticket, user: user, quantity: 2)
+        end
+
+        it 'returns the correct total price' do
+          total_price = Money.new(200000, 'USD')
+          expect(Ticket.total_price(conference, user)).to eq(total_price)
+        end
+      end
     end
   end
 end