require 'rails_helper' describe SampleMyModule, type: :model do it 'should be of class SampleMyModule' do expect(subject.class).to eq SampleMyModule end describe 'Database table' do it { should have_db_column :sample_id } it { should have_db_column :my_module_id } it { should have_db_column :assigned_by_id } it { should have_db_column :assigned_on } end describe 'Relations' do it { should belong_to(:assigned_by).class_name('User') } it { should belong_to :sample } it { should belong_to :my_module } end describe 'Should be a valid object' do it { should validate_presence_of :sample } it { should validate_presence_of :my_module } it 'should have one sample assigned per model' do sample = create :sample my_module = create :my_module, name: 'Module one' create :sample_my_module, sample: sample, my_module: my_module new_smm = build :sample_my_module, sample: sample, my_module: my_module expect(new_smm).to_not be_valid end end end