undefined method `map' error on should create model test - ruby-on-rails

Question

app/controllers/products_controller.rb:
class ProductsController < ApplicationController
before_action :set_product, only: [:show, :edit, :update, :destroy]
before_action :authenticate_user!, except: [:index, :show]
# GET /products
# GET /products.json
def index
##products = Product.all
#products = Product.all
if params[:search]
#products = Product.search(params[:search]).order("created_at DESC").paginate(page: params[:page], per_page: 5)
else
#products = Product.all.order('created_at DESC').paginate(page: params[:page], per_page: 5)
end
if session[:cart] then
#cart = session[:cart]
else
#cart = {}
end
end
# GET /products/1
# GET /products/1.json
def show
end
# GET /products/new
def new
if current_user.admin?
##product = Product.new
#product = Product.new
#categories = Category.all.map{|c| [ c.name, c.id ] }
end
end
# GET /products/1/edit
def edit
if current_user.admin?
#categories = Category.all.map{|c| [ c.name, c.id ] }
end
end
# POST /products
# POST /products.json
def create
if current_user.admin?
#product = Product.new(product_params)
#product.category_id = params[:category_id]
respond_to do |format|
if #product.save
format.html { redirect_to #product, notice: 'Product was successfully created.' }
format.json { render :show, status: :created, location: #product }
else
format.html { render :new }
format.json { render json: #product.errors, status: :unprocessable_entity }
end
end
end
end
# PATCH/PUT /products/1
# PATCH/PUT /products/1.json
def update
if current_user.admin?
#product.category_id = params[:category_id]
respond_to do |format|
if #product.update(product_params)
format.html { redirect_to #product, notice: 'Product was successfully updated.' }
format.json { render :show, status: :ok, location: #product }
else
format.html { render :edit }
format.json { render json: #product.errors, status: :unprocessable_entity }
end
end
end
end
# DELETE /products/1
# DELETE /products/1.json
def destroy
if current_user.admin?
#product.destroy
respond_to do |format|
format.html { redirect_to products_url, notice: 'Product was successfully destroyed.' }
format.json { head :no_content }
end
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_product
#product = Product.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def product_params
params.require(:product).permit(:title, :description, :photo, :price, :category, :subcategory)
end
end
app/views/products/new.html.erb:
<h1>New Product</h1>
<%= render 'form' %>
<%= link_to 'Back', products_path %>
app/views/products/_form.html.erb:
<%= form_for(#product, multipart: true) do |f| %>
<% if #product.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#product.errors.count, "error") %> prohibited this product from being saved:</h2>
<ul>
<% #product.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :title %><br>
<%= f.text_field :title %>
</div>
<div class="field">
<%= f.label :description %><br>
<%= f.text_area :description %>
</div>
<div class="field">
<%= f.label :image %><br>
<%= f.file_field :photo %>
</div>
<div class="field">
<%= f.label :price %><br>
<%= f.number_field :price, :step => "0.01" %>
</div>
<div class="field">
<%= f.label :category %><br>
<%= select_tag(:category_id, options_for_select(#categories), :prompt => "Select one!") %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
My test in test/controllers/products_controller_test.rb:
test "should create product" do
sign_in users(:admin)
assert_difference('Product.count') do
post :create, product: { category_id: #product.category, description: #product.description, photo_content_type: #product.photo_content_type, photo_file_name: #product.photo_file_name, photo_file_size: #product.photo_file_size, photo_updated_at: #product.photo_updated_at, price: #product.price, title: #product.title }
end
assert_redirected_to product_path(assigns(:product))
end
Causing this error:
Finished in 0.816541s, 24.4936 runs/s, 35.5157 assertions/s.
1) Error:
ProductsControllerTest#test_should_create_product:
ActionView::Template::Error: undefined method `map' for nil:NilClass
app/views/products/_form.html.erb:32:in `block in _app_views_products__form_html_erb__4489093195482743578_70189257075560'
app/views/products/_form.html.erb:1:in `_app_views_products__form_html_erb__4489093195482743578_70189257075560'
app/views/products/new.html.erb:3:in `_app_views_products_new_html_erb__3438187527367239596_70189257283820'
app/controllers/products_controller.rb:57:in `block (2 levels) in create'
app/controllers/products_controller.rb:52:in `create'
test/controllers/products_controller_test.rb:29:in `block (2 levels) in <class:ProductsControllerTest>'
test/controllers/products_controller_test.rb:28:in `block in <class:ProductsControllerTest>'
20 runs, 29 assertions, 0 failures, 1 errors, 0 skips
I'm running my tests with rake test:functionals. The other tests are fine but only this test is problematic.
There is even no any method named map in app/views/products/_form.html.erb:. So I don't have any idea for cause of this error.
If you want to look to the whole project: https://github.com/mertyildiran/SCOR
CHANGES:
According to answers:
In form I made this change: <%= f.collection_select(:category_id, Category.all, :id, :name) %>
In products controller: params.require(:product).permit(:title, :description, :photo, :price, :category_id)
And new version of test:
test "should create product" do
sign_in users(:admin)
image = fixture_file_upload "../../public/assets/products/1/original/" + #product.photo_file_name
puts image.inspect
assert_difference('Product.count') do
post :create, product: { category_id: #product.category, description: #product.description, photo: image, price: #product.price, title: #product.title }
end
assert_redirected_to product_path(assigns(:product))
end
We get rid of error but Failure persist, stdout:
# Running:
.......#<Rack::Test::UploadedFile:0x007f5a1894fdf8 #content_type=nil, #original_filename="ra_unisex_tshirt_x1000_fafafa-ca443f4786_front-c_235_200_225_294-bg_f8f8f8_(7).jpg", #tempfile=#<Tempfile:/tmp/ra_unisex_tshirt_x1000_fafafa-ca443f4786_front-c_235_200_225_294-bg_f8f8f8_(7).jpg20160515-31919-1j7oypa>>
F............
Finished in 0.800235s, 24.9926 runs/s, 37.4890 assertions/s.
1) Failure:
ProductsControllerTest#test_should_create_product [/home/mertyildiran/Documents/SCOR/test/controllers/products_controller_test.rb:25]:
"Product.count" didn't change by 1.
Expected: 3
Actual: 2
20 runs, 30 assertions, 1 failures, 0 errors, 0 skips
Validation Failure Cause:
<div id="error_explanation">
<h2>2 errors prohibited this product from being saved:</h2>
<ul>
<li>Photo content type is invalid</li>
<li>Photo is invalid</li>
</ul>
</div>
Fixed with this image.content_type = #product.photo_content_type

Answer 1

When you call post :create, product: ... in your test a validation is failing which causes the new view to be rendered.
The new view then causes an error by calling options_for_select(#categories) but #categories is not defined - in other words nil. options_for_select expects the argument to be an array and calls .map on nil.
Thats not the only problem - you are not nesting the input properly either.
<%= select_tag(:category_id, options_for_select(#categories), :prompt => "Select one!") %>
Would end up in params[:category_id] not params[:product][:category_id].
Instead what you want to do is use collection_select and bind it to the model:
<div class="field">
<%= f.label :category_id %><br>
<%= f.collection_select(:category_id, Category.all, :id, :name) %>
</div>
You should also ensure that you are whitelisting the correct param - and if you have a hard time keeping track of them make sure you test it as well!
def product_params
params.require(:product).permit(:title, :description, :photo, :price, :category_id, :subcategory)
end
If you want to debug exactly what attribute causes the validation failure there are a few options:
assigns(:product) will give you the #product instance variable from your controller. assert_equals(#product.errors.full_messages, []) gives you a list. You have to call the controller action first!
You can do assert_equals(#response.body, '') to get a dump of the page HTML. You have to call the controller action first!
Keep a tab on the logs with $ tail -f logs/test.log

Answer 2

From the stack trace it appears that the validation failed when trying to save the #product and the controller wants to render the new template. But you don't have the #categories variable defined for this scenario, that is probably where the map call for nil is getting from.
So, probably you should do both of the following:
add the #categories array to the failed save part of your create and update actions in your controller so that the failed-save scenario works ok
fix the test code so that the validations do not fail when creating the product.