RSpec tests for an invoice mailer

Question

How would you DRY up this RSpec code?

require "spec_helper"
describe InvoiceMailer do
 let(:user) { create(:user) }
 let(:student) { create(:student, user: user) }
 let(:body) { "And I for one will join with anyone, don't care what color you are. As long as you want change this miserable condition that exists on this earth." }
 subject(:mail) { InvoiceMailer.issue(student, body) }
 describe "issue" do
 subject(:mail) { InvoiceMailer.issue(student, body) }
 it "renders the subject" do
 expect(mail.subject).to eq "New Invoice!"
 end
 it "renders the receiver email" do
 expect(mail.to).to eq [student.user.email]
 end
 it "renders the sender email" do
 expect(mail.from).to eq ["[email protected]"]
 end
 end
 describe "rescind" do
 subject(:mail) { InvoiceMailer.rescind(student, body) }
 it "renders the subject" do
 expect(mail.subject).to eq "Invoice Rescinded!"
 end
 it "renders the receiver email" do
 expect(mail.to).to eq [student.user.email]
 end
 it "renders the sender email" do
 expect(mail.from).to eq ["[email protected]"]
 end
 end
end

Answer 1

You can use the its syntax:

require "spec_helper"
describe InvoiceMailer do
 let(:user) { create(:user) }
 let(:student) { create(:student, user: user) }
 let(:body) { "And I for one will join with anyone, don't care what color you are. As long as you want change this miserable condition that exists on this earth." }
 describe "issue" do
 subject { InvoiceMailer.issue(student, body) }
 its(:subject) { should eq "New Invoice!" }
 its(:to) { should eq [student.user.email] }
 its(:from) { should eq ["[email protected]"] }
 end
 describe "rescind" do
 subject { InvoiceMailer.rescind(student, body) }
 its(:subject) { should eq "Invoice Rescinded!" }
 its(:to) { should eq [student.user.email] }
 its(:from) { should eq ["[email protected]"] }
 end
end

You can further DRY it up using example groups

describe InvoiceMailer do
 let(:user) { create(:user) }
 let(:student) { create(:student, user: user) }
 let(:body) { "And I for one will join with anyone, don't care what color you are. As long as you want change this miserable condition that exists on this earth." }
 shared_examples_for "outgoing mail" do |method, mail_subject|
 subject { InvoiceMailer.send(method, student, body) }
 its(:subject) { should eq mail_subject }
 its(:to) { should eq [student.user.email] }
 its(:from) { should eq ["[email protected]"] }
 end
 describe "issue" do
 it_should_behave_like "outgoing mail", :issue, 'New Invoice!'
 end
 describe "rescind" do
 it_should_behave_like "outgoing mail", :rescind, 'Invoice Rescinded!'
 end
end

• niftygrifty: Thanks for this answer! I don't usually like its but in this case it's very readable. I feel like there is still a lot of duplication between the the issue and rescind describe blocks though. The only differences between the two are the methods on InvoiceMailer and the subject. Any thoughts?
• Uri Agassi: Added an option with example groups
• niftygrifty: Oh! That's exactly what I was looking for!