[ruby/irb] Support inspecting BasicObject

(https://github.com/ruby/irb/pull/541)

https://github.com/ruby/irb/commit/1dc2a406a3

1 files changed, 7 insertions, 1 deletions

diff --git a/lib/irb/color_printer.rb b/lib/irb/color_printer.rb
index 1127bcecb4..a4eeb140cd 100644
--- a/lib/irb/color_printer.rb
+++ b/lib/irb/color_printer.rb
@@ -4,6 +4,10 @@ require_relative 'color'
 
 module IRB
   class ColorPrinter < ::PP
+    METHOD_IS_A = Object.instance_method(:is_a?)
+    METHOD_RESPOND_TO = Object.instance_method(:respond_to?)
+    METHOD_INSPECT = Object.instance_method(:inspect)
+
     class << self
       def pp(obj, out = $>, width = screen_width)
         q = ColorPrinter.new(out, width)
@@ -22,9 +26,11 @@ module IRB
     end
 
     def pp(obj)
-      if obj.is_a?(String)
+      if METHOD_IS_A.bind(obj).call(String)
         # Avoid calling Ruby 2.4+ String#pretty_print that splits a string by "\n"
         text(obj.inspect)
+      elsif !METHOD_RESPOND_TO.bind(obj).call(:inspect)
+        text(METHOD_INSPECT.bind(obj).call)
       else
         super
       end