Use existing instances for LineEditor and Config

lib/reline.rb

@@ -46,10 +46,13 @@ module Reline
     end
 
     def push(*val)
+      diff = size + val.size - @@config.history_size
+      shift(diff) if diff > 0
       super(*(val.map{ |v| String.new(v, encoding: Encoding::default_external) }))
     end
 
     def <<(val)
+      shift if size + 1 > @@config.history_size
       super(String.new(val, encoding: Encoding::default_external))
     end
 

test/reline/test_key_actor_emacs.rb

@@ -4,9 +4,9 @@ class Reline::KeyActor::Emacs::Test < Reline::TestCase
   def setup
     Reline.send(:test_mode)
     @prompt = '> '
-    @config = Reline::Config.new # Emacs mode is default
+    @config = Reline.class_variable_get(:@@config) # Emacs mode is default
+    @line_editor = Reline.class_variable_get(:@@line_editor)
     @encoding = (RELINE_TEST_ENCODING rescue Encoding.default_external)
-    @line_editor = Reline::LineEditor.new(@config)
     @line_editor.reset(@prompt, @encoding)
   end
 

test/reline/test_key_actor_vi.rb

@@ -4,12 +4,13 @@ class Reline::KeyActor::ViInsert::Test < Reline::TestCase
   def setup
     Reline.send(:test_mode)
     @prompt = '> '
-    @config = Reline::Config.new
+    @config = Reline.class_variable_get(:@@config) # Emacs mode is default
     @config.read_lines(<<~LINES.split(/(?<=\n)/))
       set editing-mode vi
     LINES
-    @line_editor = Reline::LineEditor.new(@config)
-    @line_editor.reset(@prompt, (RELINE_TEST_ENCODING rescue Encoding.default_external))
+    @line_editor = Reline.class_variable_get(:@@line_editor)
+    @encoding = (RELINE_TEST_ENCODING rescue Encoding.default_external)
+    @line_editor.reset(@prompt, @encoding)
   end
 
   def test_vi_command_mode