Extract ReplicableModel shared examples

into their own file.

ee/spec/support/shared_examples/models/concerns/blob_replicator_strategy_shared_examples.rb

@@ -20,6 +20,9 @@ RSpec.shared_examples 'a blob replicator' do
 
   it_behaves_like 'a replicator'
 
+  # This could be included in each model's spec, but including it here is DRYer.
+  include_examples 'a replicable model'
+
   describe '#handle_after_create_commit' do
     it 'creates a Geo::Event' do
       expect do
@@ -172,18 +175,5 @@ RSpec.shared_examples 'a blob replicator' do
     it 'is a Class' do
       expect(invoke_model).to be_a(Class)
     end
-
-    # For convenience (and reliability), instead of asking developers to include shared examples on each model spec as well
-    context 'replicable model' do
-      it 'defines #replicator' do
-        expect(model_record).to respond_to(:replicator)
-      end
-
-      it 'invokes replicator.handle_after_create_commit on create' do
-        expect(replicator).to receive(:handle_after_create_commit)
-
-        model_record.save!
-      end
-    end
   end
 end

ee/spec/support/shared_examples/models/concerns/replicable_model_shared_examples.rb

+# frozen_string_literal: true
+
+# Required let variables:
+#
+# - model_record: A valid, unpersisted instance of the model class
+#
+# We do not use `described_class` here, so we can include this in replicator
+# strategy shared examples instead of in *every* model spec.
+RSpec.shared_examples 'a replicable model' do
+  include EE::GeoHelpers
+
+  describe '#replicator' do
+    it 'is defined and does not raise error' do
+      expect(model_record.replicator).to be_a(Gitlab::Geo::Replicator)
+    end
+  end
+
+  it 'invokes replicator.handle_after_create_commit on create' do
+    expect(model_record.replicator).to receive(:handle_after_create_commit)
+
+    model_record.save!
+  end
+end