1 files changed, 40 insertions, 0 deletions
diff --git a/spec/support/shared_examples/models/atomic_internal_id_spec.rb b/spec/support/shared_examples/models/atomic_internal_id_spec.rb
new file mode 100644
index 00000000000..144af4fc475
--- /dev/null
+++ b/spec/support/shared_examples/models/atomic_internal_id_spec.rb
@@ -0,0 +1,40 @@
+require 'spec_helper'
+
+shared_examples_for 'AtomicInternalId' do
+  describe '.has_internal_id' do
+    describe 'Module inclusion' do
+      subject { described_class }
+
+      it { is_expected.to include_module(AtomicInternalId) }
+    end
+
+    describe 'Validation' do
+      subject { instance }
+
+      before do
+        allow(InternalId).to receive(:generate_next).and_return(nil)
+      end
+
+      it { is_expected.to validate_presence_of(internal_id_attribute) }
+      it { is_expected.to validate_numericality_of(internal_id_attribute) }
+    end
+
+    describe 'internal id generation' do
+      subject { instance.save! }
+
+      it 'calls InternalId.generate_next and sets internal id attribute' do
+        iid = rand(1..1000)
+
+        expect(InternalId).to receive(:generate_next).with(instance, scope_attrs, usage, any_args).and_return(iid)
+        subject
+        expect(instance.public_send(internal_id_attribute)).to eq(iid)
+      end
+
+      it 'does not overwrite an existing internal id' do
+        instance.public_send("#{internal_id_attribute}=", 4711)
+
+        expect { subject }.not_to change { instance.public_send(internal_id_attribute) }
+      end
+    end
+  end
+end