Always keep errors in the props

Author: skryukov

lib/inertia_rails/renderer.rb

@@ -91,6 +91,11 @@ def merge_props(shared_props, props)
 
     def computed_props
       merged_props = merge_props(shared_data, props)
+      # Always keep errors in the props
+      if merged_props.key?(:errors) && !merged_props[:errors].is_a?(BaseProp)
+        errors = merged_props[:errors]
+        merged_props[:errors] = InertiaRails.always { errors }
+      end
       deep_transform_props(merged_props).tap do |transformed_props|
         transformed_props[:_inertia_meta] = meta_tags if meta_tags.present?
       end

spec/inertia/error_sharing_spec.rb

@@ -45,5 +45,27 @@
       expect(response.body).to include(CGI::escape_html({ errors: { uh: 'oh' } }.to_json))
       expect(session[:inertia_errors]).not_to be
     end
+
+    context 'with partial update' do
+      let(:headers) do
+        {
+          'X-Inertia' => true,
+          'X-Inertia-Version' => server_version,
+          'X-Inertia-Partial-Component' => 'EmptyTestComponent',
+          'X-Inertia-Partial-Data' => 'foo',
+        }
+      end
+
+      it 'keeps errors when partial inertia request redirects' do
+        post redirect_with_inertia_errors_path, headers: headers
+        expect(response.headers['Location']).to eq(empty_test_url)
+        expect(session[:inertia_errors]).to include({ uh: 'oh' })
+
+        # Follow the redirect
+        get response.headers['Location'], headers: headers
+        expect(response.body).to include({ errors: { uh: 'oh' } }.to_json)
+        expect(session[:inertia_errors]).not_to be
+      end
+    end
   end
 end