From bbb20ca8ac848932e3bdb4faa6a670bef9cbdcb5 Mon Sep 17 00:00:00 2001
From: Darren Chang <darren.chang@tarokosoftware.com>
Date: Tue, 7 Aug 2018 14:13:41 +0800
Subject: [PATCH] Use default_rescue_handler if reponse is invalid

---
 CHANGELOG.md                  |  2 +-
 lib/grape/middleware/error.rb |  2 +-
 spec/grape/api_spec.rb        | 36 ++++++++++++++++++++---------------
 3 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1c979a78ec..93ce601275 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 #### Fixes
 
 * Your contribution here.
+* [#1776](https://github.com/ruby-grape/grape/pull/1776): Validates response processed by exception handler - [@darren987469](https://github.com/darren987469).
 
 ### 1.1.0 (8/4/2018)
 
@@ -21,7 +22,6 @@
 * [#1758](https://github.com/ruby-grape/grape/pull/1758): Fix expanding load_path in gemspec - [@2maz](https://github.com/2maz).
 * [#1765](https://github.com/ruby-grape/grape/pull/1765): Use 415 when request body is of an unsupported media type - [@jdmurphy](https://github.com/jdmurphy).
 * [#1771](https://github.com/ruby-grape/grape/pull/1771): Fix param aliases with 'given' blocks - [@jereynolds](https://github.com/jereynolds).
-* [#1776](https://github.com/ruby-grape/grape/pull/1776): Validates response processed by exception handler - [@darren987469](https://github.com/darren987469).
 
 ### 1.0.3 (4/23/2018)
 
diff --git a/lib/grape/middleware/error.rb b/lib/grape/middleware/error.rb
index d681f4a962..469c350d84 100644
--- a/lib/grape/middleware/error.rb
+++ b/lib/grape/middleware/error.rb
@@ -128,7 +128,7 @@ def run_rescue_handler(handler, error)
         end
 
         response = handler.arity.zero? ? instance_exec(&handler) : instance_exec(error, &handler)
-        valid_response?(response) ? response : error!('Internal Server Error(Invalid Response)')
+        valid_response?(response) ? response : run_rescue_handler(:default_rescue_handler, error)
       end
 
       def valid_response?(response)
diff --git a/spec/grape/api_spec.rb b/spec/grape/api_spec.rb
index 5e0edeaa87..d1fae42654 100644
--- a/spec/grape/api_spec.rb
+++ b/spec/grape/api_spec.rb
@@ -1724,24 +1724,30 @@ class CustomError < Grape::Exceptions::Base; end
       expect(last_response.body).to eq('Formatter Error')
     end
 
-    it 'validates response processed by exception handler' do
-      subject.rescue_from ArgumentError do
-        error!('rain!')
-        nil # invalid response caused by return nil
-      end
-      subject.rescue_from :all do
-        error!('rain!')
+    context 'validates response processed by exception handler' do
+      it 'calls default_rescue_handler when response is invalid' do
+        subject.rescue_from :all do
+          error!('Internal Server Error')
+          nil # invalid response caused by return nil
+        end
+        subject.get('/invalid_response') { raise 'rain!' }
+
+        expect_any_instance_of(Grape::Middleware::Error).to receive(:default_rescue_handler).and_call_original
+        get '/invalid_response'
+        expect(last_response.status).to eql 500
+        expect(last_response.body).to eq('rain!')
       end
-      subject.get('/invalid_response') { raise ArgumentError }
-      subject.get('/valid_response') { raise 'rain!' }
 
-      get '/invalid_response'
-      expect(last_response.status).to eql 500
-      expect(last_response.body).to eq('Internal Server Error(Invalid Response)')
+      it 'calls custom handler when response is valid' do
+        subject.rescue_from :all do
+          error!('Internal Server Error')
+        end
+        subject.get('/valid_response') { raise 'rain!' }
 
-      get '/valid_response'
-      expect(last_response.status).to eql 500
-      expect(last_response.body).to eq('rain!')
+        get '/valid_response'
+        expect(last_response.status).to eql 500
+        expect(last_response.body).to eq('Internal Server Error')
+      end
     end
   end