Colorize error characters

* lib/irb/color.rb (IRB::Color.scan): ignore "incomplete end of
  input" error only, to colorize invalid characters, e.g., control
  characters, and invalid symbols, as errors.

1 files changed, 15 insertions, 29 deletions

diff --git a/lib/irb/color.rb b/lib/irb/color.rb
index 5e58c2509f..c2d0084446 100644
--- a/lib/irb/color.rb
+++ b/lib/irb/color.rb
@@ -131,28 +131,23 @@ module IRB # :nodoc:
       private
 
       def scan(code, detect_compile_error:)
-        if detect_compile_error
-          pos = [1, 0]
-
-          Ripper::Lexer.new(code).scan.each do |elem|
-            str = elem.tok
-            next if ([elem.pos[0], elem.pos[1] + str.bytesize] <=> pos) <= 0
-
-            str.each_line do |line|
-              if line.end_with?("\n")
-                pos[0] += 1
-                pos[1] = 0
-              else
-                pos[1] += line.bytesize
-              end
-            end
+        pos = [1, 0]
 
-            yield(elem.event, str, elem.state)
-          end
-        else
-          ParseErrorLexer.new(code).parse.sort_by(&:pos).each do |elem|
-            yield(elem.event, elem.tok, elem.state)
+        Ripper::Lexer.new(code).scan.each do |elem|
+          str = elem.tok
+          next if !detect_compile_error and elem.message&.end_with?("meets end of file")
+          next if ([elem.pos[0], elem.pos[1] + str.bytesize] <=> pos) <= 0
+
+          str.each_line do |line|
+            if line.end_with?("\n")
+              pos[0] += 1
+              pos[1] = 0
+            else
+              pos[1] += line.bytesize
+            end
           end
+
+          yield(elem.event, str, elem.state)
         end
       end
 
@@ -171,15 +166,6 @@ module IRB # :nodoc:
       end
     end
 
-    class ParseErrorLexer < Ripper::Lexer
-      if method_defined?(:token)
-        def on_parse_error(mesg)
-          @buf.push Elem.new([lineno(), column()], __callee__, token(), state())
-        end
-      end
-    end
-    private_constant :ParseErrorLexer
-
     # A class to manage a state to know whether the current token is for Symbol or not.
     class SymbolState
       def initialize