Add integration tests for both of the above.

Suresh attempted:

Note: I cheat a bit since I update the ship date in the order controller as soon as the order is taken. Let us assume we are selling only ebooks :).

For testing whether the shipment notification mail works properly, modify UserStoriesTest.”buying a product”: 

  test "buying a product" do
    # existing code here...
    ship_date_expected = Time.now.to_date    ### new line
    post_via_redirect "/orders", ### existing line
    # existing code here...
    assert_equal "Check", order.pay_type  ### existing line
    assert_equal ship_date_expected, order.ship_date.to_date  ### new line
    # existing code here...
  end
For testing whether error notification mail works properly, add a new test: 

  test "should mail the admin when error occurs" do
    get "/carts/wibble" 
    assert_response :redirect  # should redirect to...
    assert_template "/"        # ...store index

    mail = ActionMailer::Base.deliveries.last
    assert_equal ["abc@xmail.com"], mail.to  ## replace mail id
    assert_equal "some one <depot@example.com>", mail[:from].value  ## replace contact name/mail id
    assert_equal "Depot App Error Incident", mail.subject
  end