improved error handling on responses

lib/instapaper/error.rb

@@ -4,6 +4,7 @@ module Instapaper
     # @return [Integer]
     attr_reader :code
 
+    ServiceUnavailableError = Class.new(self)
     BookmarkError = Class.new(self)
     FolderError = Class.new(self)
     HighlightError = Class.new(self)

lib/instapaper/http/request.rb

@@ -41,11 +41,23 @@ module Instapaper
         @headers = Instapaper::HTTP::Headers.new(@client, @request_method, @uri, @options).request_headers
         options_key = @request_method == :get ? :params : :form
         response = ::HTTP.with(@headers).public_send(@request_method, @uri.to_s, options_key => @options)
-        fail_if_error(parsed_response(response))
+        fail_if_error(response, raw)
+        fail_if_error_in_body(parsed_response(response))
         raw ? response.to_s : parsed_response(response)
       end
 
-      def fail_if_error(response)
+      def fail_if_error(response, raw)
+        fail Instapaper::Error::ServiceUnavailableError if response.status != 200
+        return if raw
+
+        begin
+          response.parse
+        rescue JSON::ParserError
+          fail Instapaper::Error::ServiceUnavailableError
+        end
+      end
+
+      def fail_if_error_in_body(response)
         error = error(response)
         fail(error) if error
       end

spec/instapaper/http/request_spec.rb

@@ -0,0 +1,31 @@
+require 'spec_helper'
+
+describe Instapaper::HTTP::Request do
+  let(:client) { Instapaper::Client.new(consumer_key: 'CK', consumer_secret: 'CS', oauth_token: 'OT', oauth_token_secret: 'OS') }
+
+  describe 'error handling' do
+    context 'when receiving a non-200 response' do
+      before do
+        stub_post('/api/1/folders/list')
+          .to_return(status: 503, body: '', headers: {content_type: 'application/json; charset=utf-8'})
+      end
+      it 'raises a ServiceUnavailableError' do
+        expect {
+          client.folders
+        }.to raise_error(Instapaper::Error::ServiceUnavailableError)
+      end
+    end
+
+    context 'when failing to parse json' do
+      before do
+        stub_post('/api/1/folders/list')
+          .to_return(status: 200, body: '{"key":"value}', headers: {content_type: 'application/json; charset=utf-8'})
+      end
+      it 'raises a ServiceUnavailableError' do
+        expect {
+          client.folders
+        }.to raise_error(Instapaper::Error::ServiceUnavailableError)
+      end
+    end
+  end
+end