Clean up presence validation spec

spec/models/ci/pipeline_spec.rb

@@ -36,13 +36,12 @@ describe Ci::Pipeline, :mailer do
   end
 
   describe 'modules' do
-    it_behaves_like 'AtomicInternalId' do
+    it_behaves_like 'AtomicInternalId', validate_presence: false do
       let(:internal_id_attribute) { :iid }
       let(:instance) { build(:ci_pipeline) }
       let(:scope) { :project }
       let(:scope_attrs) { { project: instance.project } }
       let(:usage) { :ci_pipelines }
-      let(:allow_nil) { true }
     end
   end
 

spec/support/shared_examples/models/atomic_internal_id_spec.rb

 require 'spec_helper'
 
-shared_examples_for 'AtomicInternalId' do
-  let(:allow_nil) { false }
-
+shared_examples_for 'AtomicInternalId' do |validate_presence: true|
   describe '.has_internal_id' do
     describe 'Module inclusion' do
       subject { described_class }
@@ -12,18 +10,30 @@ shared_examples_for 'AtomicInternalId' do
 
     describe 'Validation' do
       before do
-        allow_any_instance_of(described_class).to receive(:"ensure_#{scope}_#{internal_id_attribute}!") {}
-      end
+        allow_any_instance_of(described_class).to receive(:"ensure_#{scope}_#{internal_id_attribute}!")
 
-      it 'validates presence' do
         instance.valid?
+      end
 
-        if allow_nil
-          expect(instance.errors[internal_id_attribute]).to be_empty
-        else
+      context 'when presence validattion is required' do
+        before do
+          skip unless validate_presence
+        end
+
+        it 'validates presence' do
           expect(instance.errors[internal_id_attribute]).to include("can't be blank")
         end
       end
+
+      context 'when presence validattion is not required' do
+        before do
+          skip if validate_presence
+        end
+
+        it 'does not validate presence' do
+          expect(instance.errors[internal_id_attribute]).to be_empty
+        end
+      end
     end
 
     describe 'Creating an instance' do