feature: ability to handle standard error's descendants for unprocess…

…able

https://jira.railsc.ru/browse/ORDERS-86

Gemfile

@@ -6,6 +6,7 @@ group :development, :test do
 end
 
 gem 'mime-types', '< 3.0' if RUBY_VERSION < '2'
+gem 'rack', '< 2.0' if RUBY_VERSION < '2.2.2'
 gem 'migration_comments', '= 0.3.2' if RUBY_VERSION < '2'
 
 # Specify your gem's dependencies in apress-api.gemspec

lib/apress/api/api_controller/rescue.rb

@@ -43,6 +43,8 @@ def unprocessable(exception_or_errors)
           @errors =
             if exception_or_errors.respond_to?(:record)
               exception_or_errors.record.errors
+            elsif exception_or_errors.is_a?(StandardError)
+              {message: exception_or_errors.message}
             else
               exception_or_errors
             end

spec/controllers/api_controller/rescue_spec.rb

@@ -76,7 +76,7 @@ def index
       allow(controller).to receive(:record).and_return(record)
     end
 
-    context 'when rescued from exeption' do
+    context 'when rescued from record invalid' do
       controller do
         def index
           raise ActiveRecord::RecordInvalid.new(record)
@@ -91,6 +91,26 @@ def index
       end
     end
 
+    context 'when rescued from standard error' do
+      controller do
+        class CustomError < StandardError
+        end
+
+        rescue_from CustomError, with: :unprocessable
+
+        def index
+          raise CustomError.new("custom error")
+        end
+      end
+
+      it "renders error" do
+        get :index
+
+        expect(response.status).to eq 422
+        expect(json['errors']).to eq [{"message" => "custom error"}]
+      end
+    end
+
     context 'when called from action' do
       controller do
         def index