Rspec: How to verify if a record has been deleted?

Question

I have created a simple Rspec test to verfiy if a model created has been deleted. However, the test fails because the model still exists. Can anyone provide any assistance on how to determine if the record was actually deleted?

RSpec.describe Person, type: :model do

let(:person) {
    Person.create(
      name: "Adam",
      serial_number: "1"
    )
  }
  
  it "destroys associated relationships when person destroyed" do
  person.destroy
  expect(person).to be_empty()
  end
end

Answer 1

You have two choices. You can test that

1. a record was removed from the database

   it "removes a record from the database" do
     expect { person.destroy }.to change { Person.count }.by(-1)
   end
   

   but that doesn't tell you which record was removed.

2. Or that the exact record does not exist in the database anymore

   it "removes the record from the database" do
     person.destroy
     expect { person.reload }.to raise_error(ActiveRecord::RecordNotFound)
   end
   

   or

   it "removes the record from the database" do
     person.destroy
     expect(Person.exists?(person.id)).to be false
   end
   

   But that does not make sure that the record existed before.

A combination of both could be:

    it "removes a record from the database" do
      expect { person.destroy }.to change { Person.count }.by(-1)
      expect { person.reload }.to raise_error(ActiveRecord::RecordNotFound)
    end

Answer 2

When you delete a record from a database, an object still persists in memory. That's why expect(person).to be_empty() fails.

RSpec has the change matcher. ActiveRecord has the persisted? method. It returns false if a record is not persisted in a database.

it "destroys associated relationships when rtu destroyed" do
  expect { person.destroy }.to change(Person, :count).by(-1)
  expect(person.persisted?).to be_falsey
end

destroy is a method of a framework. As far as I know, you don't need to test its methods.

Answer 3

I think the following is a nice way to test a specific record has been removed with one expectation, while ensuring your testing the result of the action and not just the state of your test subject.

it "removes the record from the database" do
  expect { person.destroy }.to change { Person.exists?(person.id) }.to(false)
end