Wrong number of arguments Ruby while instantiating a Subclass - ruby

Question

I have 3 classes that hare related through inheritance (it's a course exercise)
I have a Brand < Product < DBHandler classes
They are in a subfolder of the project, and all of them use require to access each other:
├── class
│   ├── Brand.rb
│   ├── Category.rb
│   ├── DBHandler.rb
│   └── Product.rb
├── db
│   ├── catalogo_categorias.txt
│   ├── catalogo_marca.txt
│   ├── catalogo_producto.txt
│   └── inventario_final.txt
├── init.rb
└── README.md
Clases
The Product file has in it:
require "#{Dir.pwd}/class/DBHandler"
class Product < DBHandler
attr_reader :key, :final_price, :db
attr_accessor :name, :unit, :brand, :category, :price
def initialize(name, unit, brand, category, price)
#name = name
#unit = unit
#brand = brand
#category = category
#price = price
#final_price = set_final_price
#db = DBHandler.new
#key = set_key
end
def set_key
#key = "#{#db.how_many+1}#{self.name[0..2].upcase}3BS"
end
def set_final_price
#final_price = self.price * 1.19
end
def search_product(search_expresion)
#db.db_search(search_expresion)
end
def alta_product
#db.write(
"#{key},#{name},#{unit},#{brand},#{category},#{price},#{final_price}\n"
)
end
end
and the Brand file has:
require "#{Dir.pwd}/class/Product"
class Brand < Product
attr_reader :brand_key, :a_brands, :q_brands
attr_accessor :brand
def initialize(brand)
# use super to use parent's attributes
super(brand)
#brand_key = set_brand_key
#a_brands = get_file.read
.split("\n")
.map { |abrand| abrand.split(',') }
#q_brands = #a_brands.count
end
def set_brand_key
"#{#q_brands}#{self.brand[0..2].upcase}3BS"
end
def get_file
File.open("#{Dir.pwd}/db/catalogo_marca.txt")
end
def alta_brand
get_file.write("#{#brand_key},#{#brand}", mode: 'a')
end
end
Init file
All the files are called from the init.rb file in order to call some instance methods.
this is my Init.rb file first lines.
require './class/Product'
require './class/Brand'
require './class/DBHandler'
require './class/Category'
The problem
when I want to create a new instance of Brand class, I have tried:
brand = Brand.new(name, unit, brand, category, price) and it returns wrong number of arguments (given 5, expected 1) (ArgumentError)
brand = Brand.new(brand) and it returns wrong number of arguments (given 1, expected 5) (ArgumentError)
I don't know what may I doing wrong.
I need to create a Brand instance with only brand argument

Answer 1

Your problem is here
super(brand)
This is saying "call the parent constructor with brand as the only argument". The parent constructor is Product#initialize, which takes five arguments. So no matter how you call Brand#initialize, it's going to fail since it calls Product#initialize with the wrong number of arguments. You need to call super with all five.
But I challenge the frame. Subclassing is a very tight coupling, an "is-a" relationship. What you're claiming is that every brand is a product, and I fail to see how that's true. So rather than fixing the super call, you might reconsider your design and ask yourself if you really meant to make a subclass.