Helper #render_site_layout: Raise in dev envs

If we miss a partial, our specs should tell us.

app/helpers/alchemy/pages_helper.rb

@@ -64,9 +64,13 @@ def render_page_layout
     #
     def render_site_layout(&block)
       render current_alchemy_site, &block
-    rescue ActionView::MissingTemplate
-      warning("Site layout for #{current_alchemy_site.try(:name)} not found. Please run `rails g alchemy:site_layouts`")
-      ""
+    rescue ActionView::MissingTemplate => error
+      if Rails.env.production?
+        warning("Site layout for #{current_alchemy_site.try(:name)} not found. Please run `rails g alchemy:site_layouts`")
+        ""
+      else
+        raise error
+      end
     end
 
     # Renders a menu partial

spec/helpers/alchemy/pages_helper_spec.rb

@@ -41,9 +41,22 @@ module Alchemy
       end
 
       context "with missing partial" do
-        it "returns empty string and logges warning" do
-          expect(helper).to receive(:current_alchemy_site).twice.and_return(default_site)
-          expect(helper.render_site_layout).to eq("")
+        context "in production environment" do
+          before { allow(Rails.env).to receive(:production?).and_return(true) }
+
+          it "returns empty string and logges warning" do
+            expect(helper).to receive(:current_alchemy_site).twice.and_return(default_site)
+            expect(helper.render_site_layout).to eq("")
+          end
+        end
+
+        context "in dev or test environment" do
+          before { allow(Rails.env).to receive(:production?).and_return(false) }
+
+          it "raises missing template error" do
+            expect(helper).to receive(:current_alchemy_site).and_return(default_site)
+            expect { helper.render_site_layout }.to raise_error(ActionView::MissingTemplate)
+          end
         end
       end
     end