使用 Rspec 在 Rails 上测试 graphQL 突变，resolve 返回错误数量的参数

Question

I'm trying to test graphQL mutations but I couldn't solve the error. I want to create a book for each author

# book_type.rb
module ApiTypes
  class BookType < BaseObject
    field :id, ID, null: false
    field :author, ::ApiTypes::UserType, null: false

    def author
      User.find(current_user.id)
    end
  end
end

# mutation_type.rb
module ApiTypes
  class MutationType < ::ApiTypes::BaseObject
    field :create, mutation: ::Mutations::Book::Create
  end
end

# book/creat.rb
module Mutations
  module Book
    class Create < ::Mutations::BaseMutation

      field :create_book, ::ApiTypes::BookType, null: false
      argument :genre_id, ID, required: true

      def resolve(gener_id:)
        create_book = Book.create_book(genre_id: genre_id, author_id: current_user.id)
      end

      def ready?(**_args)
        require_current_user!
      end
    end
  end
end

create_book def in book.rb

def self.create_book(genre_id, author_id)
    # .. some checks...
    create(
      genre_id: genre_id,
      author_id: author_id
    )
  end

the test:

# book/create_spec.rb
require "rails_helper"

RSpec.describe “createBookForAuthor mutation" do
  it "creates new book” do
    user = FactoryBot.create(:user)
    genre = FactoryBot.create(:genre)

    query_string = <<-GRAPHQL
    mutation {
      createNewBook(input: { genreId: #{genre.id} }) {
        createBook {
          id
        }
      }
    }
    GRAPHQL

    result = LibrarySchema.execute(query_string, context: { current_user: user })

    expect { result }.to change { Book.count }.by(1)

  end
end

the error I get when I run the test:

Failure/Error: def self.create_book(genre_id, author_id) create( genre_id: genre_id, author_id: author_id ) error ArgumentError: wrong number of arguments (given 1, expected 2)

Answer 1

Here you use hash as single argument when invoke method:

create_book = Book.create_book(genre_id: genre_id, author_id: current_user.id)
# it's like Book.create_book({ genre_id: genre_id, author_id: current_user.id })

But your method uses two parameters:

def self.create_book(genre_id, author_id)
  # method body
end

So you need choose one of these ways and use it when define method and when call it

Using hash is more flexible

So you can define method as

def self.create_book(args)
  # use args[:genre_id] and args[:author_id] inside
end

Or may be keyword arguments

def self.create_book(genre_id:, author_id:)
  # use genre_id and author_id inside
end