Fix some rubocop warnings

.rubocop.yml

@@ -59,6 +59,9 @@ Style/NumericPredicate:
 Style/HashSyntax:
   Enabled: false
 
+Style/TernaryParentheses:
+  Enabled: false
+
 Layout/ExtraSpacing:
   AllowForAlignment: true,
   AllowBeforeTrailingComments: true

ext/oj/extconf.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'mkmf'
 require 'rbconfig'
 
@@ -6,7 +8,7 @@
 
 parts = RUBY_DESCRIPTION.split(' ')
 type = parts[0]
-type = type[4..-1] if type.start_with?('tcs-')
+type = type[4..] if type.start_with?('tcs-')
 is_windows = RbConfig::CONFIG['host_os'] =~ /(mingw|mswin)/
 platform = RUBY_PLATFORM
 version = RUBY_VERSION.split('.')
@@ -56,7 +58,7 @@
 end
 
 $CPPFLAGS += ' -Wall'
-#puts "*** $CPPFLAGS: #{$CPPFLAGS}"
+# puts "*** $CPPFLAGS: #{$CPPFLAGS}"
 # Adding the __attribute__ flag only works with gcc compilers and even then it
 # does not work to check args with varargs so just remove the check.
 CONFIG['warnflags'].slice!(/ -Wsuggest-attribute=format/)
@@ -65,4 +67,4 @@
 
 create_makefile(File.join(extension_name, extension_name))
 
-%x{make clean}
+`{make clean}`

lib/oj/active_support_helper.rb

@@ -1,15 +1,14 @@
+# frozen_string_literal: true
+
 require 'active_support/time'
 
 module Oj
-
   # Exists only to handle the ActiveSupport::TimeWithZone.
   class ActiveSupportHelper
-
     def self.createTimeWithZone(utc, zone)
       ActiveSupport::TimeWithZone.new(utc - utc.gmt_offset, ActiveSupport::TimeZone[zone])
     end
   end
-
 end
 
 Oj.register_odd(ActiveSupport::TimeWithZone, Oj::ActiveSupportHelper, :createTimeWithZone, :utc, 'time_zone.name')

lib/oj/json.rb

@@ -104,6 +104,7 @@ def parse()
     begin
       send(:remove_const, :Parser)
     rescue
+      # ignore and move on
     end
     Parser = ::JSON::Ext::Parser unless defined?(::JSON::Parser)
     self.parser = ::JSON::Ext::Parser

lib/oj/mimic.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'bigdecimal'
 begin
   require 'ostruct'
@@ -266,7 +268,7 @@ def as_json(*)
         end
       end
       def self.json_create(h)
-        if usec = h.delete('u')
+        if (usec = h.delete('u'))
           h['n'] = usec * 1000
         end
         if instance_methods.include?(:tv_nsec)