Remove MultiJson dependency and replace with JSON

iruby.gemspec

@@ -23,7 +23,6 @@ Gem::Specification.new do |s|
   s.add_dependency 'irb'
   s.add_dependency 'logger'
   s.add_dependency 'mime-types', '>= 3.3.1'
-  s.add_dependency 'multi_json', '~> 1.11'
 
   s.add_development_dependency 'pycall', '>= 1.2.1'
   s.add_development_dependency 'rake'

lib/iruby.rb

@@ -1,6 +1,6 @@
 require 'fileutils'
 require 'mime/types'
-require 'multi_json'
+require 'json'
 require 'securerandom'
 require 'openssl'
 require 'tempfile'

lib/iruby/input/form.rb

@@ -63,7 +63,7 @@ def widget_html
       end
 
       def submit
-        result = MultiJson.load(Kernel.instance.session.recv_input)
+        result = JSON.parse(Kernel.instance.session.recv_input)
 
         unless result.has_key? @id
           submit
@@ -74,4 +74,4 @@ def submit
       end
     end
   end
-end
+end

lib/iruby/kernel.rb

@@ -38,7 +38,7 @@ class << self
     ].freeze
 
     def initialize(config_file, session_adapter_name=nil)
-      @config = MultiJson.load(File.read(config_file))
+      @config = JSON.parse(File.read(config_file))
       IRuby.logger.debug("IRuby kernel start with config #{@config}")
       Kernel.instance = self
 

lib/iruby/session/mixin.rb

@@ -5,10 +5,10 @@ module SessionSerialize
     private
 
     def serialize(idents, header, metadata = nil, content)
-      msg = [MultiJson.dump(header),
-             MultiJson.dump(@last_recvd_msg ? @last_recvd_msg[:header] : {}),
-             MultiJson.dump(metadata || {}),
-             MultiJson.dump(content || {})]
+      msg = [JSON.generate(header),
+             JSON.generate(@last_recvd_msg ? @last_recvd_msg[:header] : {}),
+             JSON.generate(metadata || {}),
+             JSON.generate(content || {})]
       frames = ([*idents].compact.map(&:to_s) << DELIM << sign(msg)) + msg
       IRuby.logger.debug "Sent #{frames.inspect}"
       frames
@@ -28,10 +28,10 @@ def unserialize(msg)
       raise 'Invalid signature' unless s == sign(msg_list[1..-1])
       {
         idents:        idents,
-        header:        MultiJson.load(header),
-        parent_header: MultiJson.load(parent_header),
-        metadata:      MultiJson.load(metadata),
-        content:       MultiJson.load(content),
+        header:        JSON.parse(header),
+        parent_header: JSON.parse(parent_header),
+        metadata:      JSON.parse(metadata),
+        content:       JSON.parse(content),
         buffers:       buffers
       }
     end

test/helper.rb

@@ -1,6 +1,5 @@
 require "iruby"
 require "json"
-require 'multi_json'
 require "pathname"
 require "rbconfig"
 require "test/unit"