Extract parsing JSON

lib/gitlab/prometheus_client.rb

@@ -85,8 +85,6 @@ module Gitlab
       path = api_path(type)
       response = get(path, args)
       handle_response(response)
-    rescue JSON::ParserError
-      raise PrometheusClient::Error, 'Parsing response failed'
     rescue RestClient::ExceptionWithResponse => ex
       if ex.response
         handle_exception_response(ex.response)
@@ -109,7 +107,7 @@ module Gitlab
     end
 
     def handle_response(response)
-      json_data = JSON.parse(response.body)
+      json_data = parse_json(response.body)
       if response.code == 200 && json_data['status'] == 'success'
         json_data['data'] || {}
       else
@@ -121,18 +119,22 @@ module Gitlab
       if response.code == 200 && response['status'] == 'success'
         response['data'] || {}
       elsif response.code == 400
-        json_data = JSON.parse(response.body)
+        json_data = parse_json(response.body)
         raise PrometheusClient::QueryError, json_data['error'] || 'Bad data received'
       else
         raise PrometheusClient::Error, "#{response.code} - #{response.body}"
       end
-    rescue JSON::ParserError
-      raise PrometheusClient::Error, 'Parsing response failed'
     end
 
     def get_result(expected_type)
       data = yield
       data['result'] if data['resultType'] == expected_type
     end
+
+    def parse_json(response_body)
+      JSON.parse(response_body)
+    rescue JSON::ParserError
+      raise PrometheusClient::Error, 'Parsing response failed'
+    end
   end
 end