Rspec test does what it should but displays failure

Question

I'm working on a model test which looks like this:

require 'rails_helper'

RSpec.describe Demand, type: :model do
 it 'has a valid factory' do
    expect(create(:demand)).to be_valid
 end

 it 'is invalid without a parent_id' do
    expect(create(:demand, parent_id: nil)).to_not be_valid
 end
end

now the second test "is invalid without a parent_id" fails with this message:

Demand is invalid without a parent_id
 Failure/Error: expect(create(:demand, parent_id: nil)).to_not be_valid

 ActiveRecord::RecordInvalid:
   Validation failed: Parent can't be blank

This feels weird because the record tells me that it can't be blank - that's exactly what I'm testing, isn't it? Any suggestions?

EDIT: I found the mistake. Check out the answer below.

Answer 1

In case someone makes the same mistake, here's the answer:

it 'is invalid without a parent_id' do
  expect(build(:demand, parent_id: nil)).to_not be_valid
end

It needs to be "build" instead of "create".