ControllerTest error, Couldn't find Transaction with 'id'= - ruby-on-rails

Question

The Show action for my Controller is not passing the unit test. I'm getting an error in my ControllerTest. Here is the error I get from 'rake test':
> ERROR["test_should_get_show", TransactionsControllerTest, 2015-07-18
> 00:30:18 -0400] test_should_get_show#TransactionsControllerTest
> (1437193818.29s) ActiveRecord::RecordNotFound:
> ActiveRecord::RecordNotFound: Couldn't find Transaction with 'id'=
> app/controllers/transactions_controller.rb:21:in `show'
> test/controllers/transactions_controller_test.rb:6:in `block in <class:TransactionsControllerTest>'
> app/controllers/transactions_controller.rb:21:in `show'
> test/controllers/transactions_controller_test.rb:6:in `block in <class:TransactionsControllerTest>'
>
> 5/5:
> [=======================================================================================================================] 100% Time: 00:00:00, Time: 00:00:00
>
> Finished in 0.24993s 5 tests, 4 assertions, 0 failures, 1 errors, 0
> skips
Despite this error, the view is successfully generates the page in the browser when I use this url:
http://localhost:3000/transactions/1
So, there is an error somewhere. It's not failing.
transactions_controller.rb
class TransactionsController < ApplicationController
def new
#transaction = Transaction.new
end
def create
#transaction = Transaction.new(transaction_params)
if #transaction.save
# Handle a successful save.
else
render 'new'
end
end
def index
#transactions = Transaction.all
end
def show
#transaction = Transaction.find(params[:id]) #this is row 21
end
private
def transaction_params
params.require(:transaction).permit(:company, :month, :account_code, :description, :transaction_amount)
end
end
transaction_controller_test.rb
require 'test_helper'
class TransactionsControllerTest < ActionController::TestCase
test "should get show" do
transaction = Transaction.create
get :show, id: transaction.id #this is row 6
assert_response :success
end
end
The following fixture was automatically generated by rails. I'm new at rails and have to admit that I don't really understand fixtures.
transactions.yml
one:
company: MyString
month: 2015-06-19
account_code: MyString
description: MyString
transaction_amount: 1.5
two:
company: MyString
month: 2015-06-19
account_code: MyString
description: MyString
transaction_amount: 1.5
In my routes file, I'm setting the root to the index action. I plan to access the show action via the url http://localhost:3000/transactions/1 and (as mentioned above) it actually works.
routes.rb
Rails.application.routes.draw do
root 'transactions#index'
resources :transactions
end
transaction.rb
class Transaction < ActiveRecord::Base
validates :month, presence: true
validates :account_code, presence: true
end
transaction_test.rb
require 'test_helper'
class TransactionTest < ActiveSupport::TestCase
def setup
##transaction = transactions(:one)
#transaction = Transaction.new(company: "Inc", month: Date.new(2015,6,15).to_s,
account_code: "80-32100-12-1201-60010",
description: "Salaries & Wages - Histo Gross 1", transaction_amount: 100000)
end
test "should be valid" do
assert #transaction.valid?
end
test "month should be present" do
#transaction.month = " "
assert_not #transaction.valid?
end
test "account_code should be present" do
#transaction.account_code = " "
assert_not #transaction.valid?
end
test "month cannot be a string" do #not sure if this is worth anything at all
#transaction.month = "xxxxxxxxxxxx"
assert_not #transaction.valid?
end
end
The test auto generated by Rails (before I modified it) was very simple:
require 'test_helper'
class TransactionsControllerTest < ActionController::TestCase
test "should get show" do
get :show
assert_response :success
end
end
I modified it to the current version above because (I believe) the test should first create a transaction and then reference id somehow. But I'm not sure I did this correctly.
I've seen questions similar to this on Stackoverflow. For instance, this question was helpful, but didn't quite get me there
Count; find User with id= Minitest
NOTE: Initially, I set up the Controller incorrectly. I set it up as a singular "TransactionController" and changed it to the plural "TransactionsController". So I had to change the name in the unit test also. Perhaps this has had an effect on the app.
So... questions:
why is the unit test failing while the show action is actually
working in the browser?
How might I change the code in the unit test so it recognizes that
I'm using transaction_params?
Do I have to modify the fixtures when I make changes to the
unit_test or the controller?

Answer 1

Ok, so coorasse's suggestion to use create! forced the app to uncover a validation error. The initial error (Couldn't find Transaction with 'id'= ) was replaced with a new error:
ActiveRecord::RecordInvalid: Validation failed: Month can't be blank,
Account code can't be blank
This was confusing because it leads me to think of a model validation error. Why am I getting a model validation error in a ControllerTest? Also, the transaction.rb model clearly shows that that I've added validations to satisfy the presence of Month and AccountCode.
So, I spent some time reading through "A Guide to Testing Rails Applications" on RailsGuides
http://guides.rubyonrails.org/testing.html
All the way down in Section 8, it shows how to include a block of code before each test. Here is the new transaction_controller_test
transaction_controller_test.rb (REVISED)
require 'test_helper'
class TransactionsControllerTest < ActionController::TestCase
# called before every single test
def setup
#transaction = transactions(:one)
end
test "should get show" do
get :show, id: #transaction.id
assert_response :success
end
end
After this the test passed! Unfortunately, the RailsGuides doesn't tell me why I would want to use setup in a controller test. If any smart Rails gurus has some guidance on this, your comments would be appreciated.