response: parse: Include input JSON in Error, on JSON parsing errors (#…

…32)

For example, when the input is `["header", :{"return_code":-77}}`, a
parse error.
The error is then as follows.
```
`parse': unexpected token at ':{"return_code":-77}}' (JSON::ParserError)
```

Include the input JSON in the error since the error does not include the
full input JSON, making it difficult to debug.

---------

Co-authored-by: Sutou Kouhei <[email protected]>

lib/groonga/client/error.rb

@@ -18,5 +18,35 @@ module Groonga
   class Client
     class Error < StandardError
     end
+
+    class ErrorResponse < Error
+      attr_reader :response
+      def initialize(response)
+        @response = response
+        command = @response.command
+        status_code = @response.status_code
+        error_message = @response.error_message
+        message = "failed to execute: "
+        message << "#{command.command_name}: #{status_code}: "
+        message << "<#{error_message}>: "
+        message << command.to_command_format
+        super(message)
+      end
+    end
+
+    class InvalidResponse < Error
+      attr_reader :command
+      attr_reader :raw_response
+      def initialize(command, raw_response, error_message)
+        @command = command
+        @raw_response = raw_response
+        message = +"invalid response: "
+        message << "#{command.command_name}: "
+        message << "#{error_message}: "
+        message << "<#{command.to_command_format}>: "
+        message << "<#{raw_response}>"
+        super(message)
+      end
+    end
   end
 end

lib/groonga/client/request/error.rb

@@ -19,23 +19,9 @@
 module Groonga
   class Client
     module Request
-      class Error < Client::Error
-      end
-
-      class ErrorResponse < Error
-        attr_reader :response
-        def initialize(response)
-          @response = response
-          command = @response.command
-          status_code = @response.status_code
-          error_message = @response.error_message
-          message = "failed to execute: "
-          message << "#{command.command_name}: #{status_code}: "
-          message << "<#{error_message}>: "
-          message << command.to_command_format
-          super(message)
-        end
-      end
+      # For backward compatibility
+      Error = Client::Error
+      ErrorResponse = Client::ErrorResponse
     end
   end
 end

lib/groonga/client/response/base.rb

@@ -73,9 +73,16 @@ def parse(command, raw_response)
               callback = command["callback"]
               if callback and
                   /\A#{Regexp.escape(callback)}\((.+)\);\z/ =~ raw_response
-                response = JSON.parse($1)
+                json = $1
               else
-                response = JSON.parse(raw_response)
+                json = raw_response
+              end
+              begin
+                response = JSON.parse(json)
+              rescue JSON::ParserError => error
+                raise InvalidResponse.new(command,
+                                          raw_response,
+                                          "invalid JSON: #{error}")
               end
               if response.is_a?(::Array)
                 header, body = response

test/response/test-base.rb

@@ -222,5 +222,20 @@ def test_jsonp
       response = Groonga::Client::Response::Base.parse(command, raw_response)
       assert_equal(1396012478, response.body["start_time"])
     end
+
+    def test_invalid_json
+      command = Groonga::Command::Base.new("cancel")
+      raw_response = '["header", :{"return_code":-77}}'
+      begin
+        JSON.parse(raw_response)
+      rescue JSON::ParserError => error
+        parse_error_message = "invalid JSON: #{error}"
+      end
+      error = Groonga::Client::InvalidResponse.new(command, raw_response, parse_error_message)
+
+      assert_raise(error) do
+        Groonga::Client::Response::Base.parse(command, raw_response)
+      end
+    end
   end
 end