After years being out of the Rails ecosystem I was curious what is the difference between let and let! in rspec tests. I just forgot.
There is a simple case to demonstrate:
require 'rails_helper'
RSpec.describe User, type: :model do
describe 'Creating.' do
let!(:user) { create(:user) }
it 'Exists' do
expect(User.count).to eq 1
end
end
end
1) User Creating. Exists
Failure/Error: expect(User.count).to eq 1
And with let!
require 'rails_helper'
RSpec.describe User, type: :model do
describe 'Creating.' do
let!(:user) { create(:user) }
it 'Exists' do
expect(User.count).to eq 1
end
end
end
It gives: User Creating. Exists
Conclusion
With let we create an object when we first time to use it.
With let! we create an object when we declare it.
Happy Coding!
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