Adding logic to Admin::BaseController to standardise rendering of data with AMS

app/controllers/spree/admin/base_controller_decorator.rb

@@ -66,4 +66,23 @@ Spree::Admin::BaseController.class_eval do
   def json_request?
     request.format.json?
   end
+
+  def render_as_json(data, options={})
+    ams_prefix = options.delete :ams_prefix
+    if [Array, ActiveRecord::Relation].include? data.class
+      render options.merge(json: data, each_serializer: serializer(ams_prefix))
+    else
+      render options.merge(json: data, serializer: serializer(ams_prefix))
+    end
+  end
+
+  def serializer(ams_prefix)
+    if ams_prefix_whitelist.include?(ams_prefix) || ams_prefix.nil?
+      prefix = ams_prefix.andand.classify || ""
+      name = controller_name.classify
+      "Api::Admin::#{prefix}#{name}Serializer".constantize
+    else
+      raise "Suffix '#{ams_prefix}' not found in ams_prefix_whitelist for #{self.class.name}."
+    end
+  end
 end

spec/controllers/spree/admin/base_controller_spec.rb

@@ -35,4 +35,82 @@ describe Spree::Admin::BaseController do
         "Until you set these up, customers will not be able to shop at these hubs."
     end
   end
+
+  describe "rendering as json ActiveModelSerializer" do
+    context "when data is an object" do
+      let(:data) { { attr: 'value' } }
+
+      context "when an ams prefix is passed" do
+        let(:prefix) { "prefix" }
+
+        it "passes a prefix to the serializer method and renders with serializer" do
+          expect(controller).to receive(:serializer).with(prefix) { "SerializerClass" }
+          expect(controller).to receive(:render).with({ json: data, serializer: "SerializerClass" })
+          controller.send(:render_as_json, data, ams_prefix: prefix)
+        end
+      end
+
+      context "when no ams prefix is passed" do
+        let(:prefix) { "prefix" }
+
+        it "does not pass a prefix to the serializer method and renders with serializer" do
+          expect(controller).to receive(:serializer).with(prefix) { "SerializerClass" }
+          expect(controller).to receive(:render).with({ json: data, serializer: "SerializerClass" })
+          controller.send(:render_as_json, data, ams_prefix: prefix)
+        end
+      end
+    end
+
+    context "when data is an array" do
+      let(:data) { [{ attr: 'value' }] }
+
+      context "when an ams prefix is passed" do
+        let(:prefix) { "prefix" }
+
+        it "passes a prefix to the serializer method and renders with each_serializer" do
+          expect(controller).to receive(:serializer).with(prefix) { "SerializerClass" }
+          expect(controller).to receive(:render).with({ json: data, each_serializer: "SerializerClass" })
+          controller.send(:render_as_json, data, ams_prefix: prefix)
+        end
+      end
+
+      context "when no ams prefix is passed" do
+        let(:prefix) { "prefix" }
+
+        it "does not pass a prefix to the serializer method and renders with each_serializer" do
+          expect(controller).to receive(:serializer).with(prefix) { "SerializerClass" }
+          expect(controller).to receive(:render).with({ json: data, each_serializer: "SerializerClass" })
+          controller.send(:render_as_json, data, ams_prefix: prefix)
+        end
+      end
+    end
+  end
+
+  describe "determining the name of the serializer to be used" do
+    before do
+      class Api::Admin::AllowedPrefixAnonymouSerializer;end;
+      class Api::Admin::AnonymouSerializer;end;
+      allow(controller).to receive(:ams_prefix_whitelist) { ['allowed_prefix'] }
+    end
+
+    context "when a prefix is passed in" do
+      context "and the prefix appears in the whitelist" do
+        it "returns the requested serializer" do
+          expect(controller.send(:serializer, 'allowed_prefix')).to eq Api::Admin::AllowedPrefixAnonymouSerializer
+        end
+      end
+
+      context "and the prefix does not appear in the whitelist" do
+        it "raises an error" do
+          expect{controller.send(:serializer, 'other_prefix')}.to raise_error RuntimeError
+        end
+      end
+    end
+
+    context "when no prefix is passed in" do
+      it "returns the default serializer" do
+        expect(controller.send(:serializer, nil)).to eq Api::Admin::AnonymouSerializer
+      end
+    end
+  end
 end