User spec sample for students

user_spec.rb

require 'rails_helper'

RSpec.describe User, type: :model do
  subject { described_class.new(params) }

  let(:params) do
    {
      name: 'John'
    }
  end

  describe 'validations' do
    it { should validate_presence_of(:name) }
  end

  describe 'associations' do
    it { should have_many(:books) }
  end

  describe '#read?' do
    let(:user) { subject.save }
    let(:book_title) { 'Book title' }

    before do
      user
      # book
    end

    context 'when book has been read by a user' do
      # let(:book) { FactoryBot.create(:book, user: subject,
      #                                title: book_title, read: true) }

      # it { expect(subject.read?(book_title)).to eq true }

      let(:books_relation_double) { double }

      before do
        allow(subject).to receive(:books).and_return(books_relation_double)
      end

      it do
        expect(books_relation_double).to receive(:exists?)
                                           .with(title: book_title,
                                                 read: true)
                                           .and_return(true)
        expect(subject.read?(book_title)).to eq true
      end
    end

    context 'when book has not been read by a user' do
      let(:book) { FactoryBot.create(:book, user: subject,
                                     title: book_title, read: false) }

      it { expect(subject.read?(book_title)).to eq false }
    end
  end
end