dry_test_setup_let_subject

🎭 DRY Test Setup with let and subject

Use let to lazily define variables and subject to declare the primary object under test. This keeps your setup DRY and focused only on what each example needs. Because let is memoized per example, it helps avoid unexpected side effects between tests.

# spec/models/user_spec.rb
describe User, type: :model do
  subject(:user) { build(:user, admin: is_admin) }
  let(:is_admin) { true }

  it 'is an admin if flagged' do
    expect(user).to be_admin
  end

  context 'when not flagged' do
    let(:is_admin) { false }

    it 'is not an admin' do
      expect(user).not_to be_admin
    end
  end
end