Validate associations

RSpec.describe User, type: :model do
  # Association test
  # ensure User model has a 1:m relationship with the Event model
  it { should have_many(:events).dependent(:destroy) }
	it { should belong_to(:user) }
  # Validation tests
  # ensure columns are present before saving
  it { should validate_presence_of(:first_name) }
  it { should validate_presence_of(:last_name) }
  it { should validate_presence_of(:email) }
end

Validate boolean attribute

You can't effectively validate a bool attribute. Theoretically you validate as such:

it { should validate_inclusion_of(:notify).in_array([true, false])  }

However if you do so, RSpec will complaint:

Warning from shoulda-matchers:

You are using `validate_inclusion_of` to assert that a boolean column
allows boolean values and disallows non-boolean ones. Be aware that it
is not possible to fully test this, as boolean columns will
automatically convert non-boolean values to boolean ones. Hence, you
should consider removing this test.
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