HABTM Association with FactoryGirl - ruby-on-rails

Question

Have looked through and tried most examples and still cannot create a working HABTM. No matter how the CaseTrack and CaseTrackValue factories are constructed, I'm not able to find the CaseTrackValue[] in CaseTrack. Shouldn't creating CaseTrack properly provide a CaseTrackValue param within CaseTrack.
BTW: the only working association for HABTM seems to be putting
case_track_values { |a| [a.association(:case_track_value)] } in CaseTrack.
class CaseTrack
has_and_belongs_to_many CaseTrackValue
end
class CaseTrackValue
has_and_belongs_to_many CaseTrack
end
Rspec
it 'may exercise the create action' do
post '<route>', params: {case_track: attributes_for(:case_track)}
end
end
class CaseTrackController < ApplicationController
private:
def case_track_params
params.require(:case_track).permit(:name, :active, {case_track_values:[]})
end
end

Answer 1

Take a look at HABTM factories working in one of my projects. I put here the whole setup within a common example for you could understand it deeper and other stackoverflowers could easily adapt that example for their use cases.
So we have books and categories. There could be book belonging to many categories and there could be category with many books in it.
models/book.rb
class Book < ActiveRecord::Base
has_and_belongs_to_many :categories
end
models/category.rb
class Category < ActiveRecord::Base
has_and_belongs_to_many :books
end
factories/books.rb
FactoryGirl.define do
factory :book do
# factory to create one book with 1-3 categories book belongs to
factory :book_with_categories do
transient do
ary { array_of(Book) }
end
after(:create) do |book, ev|
create_list(:category, rand(1..3), books: ev.ary.push(book).uniq)
end
end
#factory to create a book and one category book belongs to
factory :book_of_category do
after(:create) do |book, ev|
create(:category, books: [book])
end
end
end
end
factories/categories.rb
FactoryGirl.define do
factory :category do
#factory to create category with 3-10 books belong to it
factory :category_with_books do
transient do
ary { array_of(Category) }
num { rand(3..10) }
end
after(:create) do |cat, ev|
create_list(:book, ev.num,
categories: ev.ary.push(cat).uniq)
end
end
end
end
My helper method which you have to put somewhere in spec/support and then include it where you need it:
# method returns 0-3 random objects of some Class (obj)
# for example 0-3 categories for you could add them as association
# to certain book
def array_of(obj)
ary = []
if obj.count > 0
Random.rand(0..3).times do
item = obj.all.sample
ary.push(item) unless ary.include?(item)
end
end
ary
end