Reline::ANSI is general io. Reline::GeneralIO is not.

Reline::ANSI has a partial non-tty supporting code. It should be a general io.
Reline::GeneralIO should be renamed because it is actually not a general io but an unusable io only for test usage.

lib/reline.rb

@@ -258,7 +258,6 @@ def readmultiline(prompt = '', add_hist = false, &confirm_multiline_termination)
         raise ArgumentError.new('#readmultiline needs block to confirm multiline termination')
       end
 
-      Reline.update_iogate
       io_gate.with_raw_input do
         inner_readline(prompt, add_hist, true, &confirm_multiline_termination)
       end
@@ -279,7 +278,6 @@ def readmultiline(prompt = '', add_hist = false, &confirm_multiline_termination)
     end
 
     def readline(prompt = '', add_hist = false)
-      Reline.update_iogate
       io_gate.with_raw_input do
         inner_readline(prompt, add_hist, false)
       end
@@ -324,7 +322,7 @@ def readline(prompt = '', add_hist = false)
       line_editor.auto_indent_proc = auto_indent_proc
       line_editor.dig_perfect_match_proc = dig_perfect_match_proc
       pre_input_hook&.call
-      unless Reline::IOGate == Reline::GeneralIO
+      unless Reline::IOGate == Reline::TestDumbIO
         @dialog_proc_list.each_pair do |name_sym, d|
           line_editor.add_dialog_proc(name_sym, d.dialog_proc, d.context)
         end
@@ -468,7 +466,7 @@ def ambiguous_width
     end
 
     private def may_req_ambiguous_char_width
-      @ambiguous_width = 2 if io_gate == Reline::GeneralIO or !STDOUT.tty?
+      @ambiguous_width = 2 if io_gate == Reline::TestDumbIO || !STDIN.tty? || !STDOUT.tty?
       return if defined? @ambiguous_width
       io_gate.move_cursor_column(0)
       begin
@@ -562,38 +560,25 @@ def self.ungetc(c)
   def self.line_editor
     core.line_editor
   end
-
-  def self.update_iogate
-    return if core.config.test_mode
-
-    # Need to change IOGate when `$stdout.tty?` change from false to true by `$stdout.reopen`
-    # Example: rails/spring boot the application in non-tty, then run console in tty.
-    if ENV['TERM'] != 'dumb' && core.io_gate == Reline::GeneralIO && $stdout.tty?
-      require 'reline/ansi'
-      remove_const(:IOGate)
-      const_set(:IOGate, Reline::ANSI)
-    end
-  end
 end
 
-require 'reline/general_io'
-io = Reline::GeneralIO
-unless ENV['TERM'] == 'dumb'
-  case RbConfig::CONFIG['host_os']
-  when /mswin|msys|mingw|cygwin|bccwin|wince|emc/
-    require 'reline/windows'
-    tty = (io = Reline::Windows).msys_tty?
-  else
-    tty = $stdout.tty?
-  end
+require 'reline/test_dumb_io'
+Reline::GeneralIO = Reline::TestDumbIO
+Reline.deprecate_constant :GeneralIO
+
+if ENV['TERM'] == 'dumb'
+  io = Reline::TestDumbIO
+elsif /mswin|msys|mingw|cygwin|bccwin|wince|emc/.match?(RbConfig::CONFIG['host_os'])
+  require 'reline/windows'
+  io = Reline::Windows unless Reline::Windows.msys_tty?
 end
-Reline::IOGate = if tty
+unless io
   require 'reline/ansi'
-  Reline::ANSI
-else
-  io
+  io = Reline::ANSI
 end
 
+Reline::IOGate = io
+
 Reline::Face.load_initial_configs
 
 Reline::HISTORY = Reline::History.new(Reline.core.config)

lib/reline/ansi.rb

@@ -170,12 +170,10 @@ def self.inner_getc(timeout_second)
       Reline.core.line_editor.handle_signal
     end
     c = @@input.getbyte
-    (c == 0x16 && @@input.raw(min: 0, time: 0, &:getbyte)) || c
+    (c == 0x16 && @@input.tty? && @@input.raw(min: 0, time: 0, &:getbyte)) || c
   rescue Errno::EIO
     # Maybe the I/O has been closed.
     nil
-  rescue Errno::ENOTTY
-    nil
   end
 
   @@in_bracketed_paste_mode = false
@@ -263,6 +261,8 @@ def self.cursor_pos
     begin
       res = +''
       m = nil
+      raise Errno::ENOTTY unless @@input.tty? && @@output.tty?
+
       @@input.raw do |stdin|
         @@output << "\e[6n"
         @@output.flush
@@ -284,7 +284,7 @@ def self.cursor_pos
         buf = @@output.pread(@@output.pos, 0)
         row = buf.count("\n")
         column = buf.rindex("\n") ? (buf.size - buf.rindex("\n")) - 1 : 0
-      rescue Errno::ESPIPE
+      rescue Errno::ESPIPE, IOError
         # Just returns column 1 for ambiguous width because this I/O is not
         # tty and can't seek.
         row = 0

lib/reline/line_editor.rb

@@ -446,6 +446,7 @@ def update_dialogs(key = nil)
   def render_finished
     clear_rendered_lines
     render_full_content
+    @output.flush
   end
 
   def clear_rendered_lines
@@ -538,6 +539,7 @@ def render_differential
     Reline::IOGate.move_cursor_column wrapped_cursor_x
     Reline::IOGate.move_cursor_down y - cursor_y
     @rendered_screen.cursor_y = y
+    @output.flush
     new_lines.size - y
   end
 
@@ -1110,6 +1112,7 @@ def input_key(key)
       end
     end
     if key.char.nil?
+      process_insert(force: true)
       if @first_char
         @eof = true
       end

lib/reline/general_io.rb → lib/reline/test_dumb_io.rb

@@ -1,6 +1,6 @@
 require 'io/wait'
 
-class Reline::GeneralIO
+class Reline::TestDumbIO
   RESET_COLOR = '' # Do not send color reset sequence
 
   def self.reset(encoding: nil)

test/reline/helper.rb

@@ -23,7 +23,7 @@ class <<self
     def test_mode(ansi: false)
       @original_iogate = IOGate
       remove_const('IOGate')
-      const_set('IOGate', ansi ? Reline::ANSI : Reline::GeneralIO)
+      const_set('IOGate', ansi ? Reline::ANSI : Reline::TestDumbIO)
       if ENV['RELINE_TEST_ENCODING']
         encoding = Encoding.find(ENV['RELINE_TEST_ENCODING'])
       else
@@ -34,7 +34,7 @@ def test_mode(ansi: false)
       def IOGate.get_screen_size
         [24, 80]
       end
-      Reline::GeneralIO.reset(encoding: encoding) unless ansi
+      Reline::TestDumbIO.reset(encoding: encoding) unless ansi
       core.config.instance_variable_set(:@test_mode, true)
       core.config.reset
     end
@@ -44,7 +44,7 @@ def test_reset
       IOGate.define_singleton_method(:get_screen_size, @original_get_screen_size)
       remove_const('IOGate')
       const_set('IOGate', @original_iogate)
-      Reline::GeneralIO.reset
+      Reline::TestDumbIO.reset
       Reline.instance_variable_set(:@core, nil)
     end
 
@@ -146,7 +146,7 @@ def assert_byte_pointer_size(expected)
       expected.bytesize, byte_pointer,
       <<~EOM)
         <#{expected.inspect} (#{expected.encoding.inspect})> expected but was
-        <#{chunk.inspect} (#{chunk.encoding.inspect})> in <Terminal #{Reline::GeneralIO.encoding.inspect}>
+        <#{chunk.inspect} (#{chunk.encoding.inspect})> in <Terminal #{Reline::TestDumbIO.encoding.inspect}>
       EOM
   end
 

test/reline/test_reline.rb

@@ -375,7 +375,7 @@ def test_read_io
   def test_dumb_terminal
     lib = File.expand_path("../../lib", __dir__)
     out = IO.popen([{"TERM"=>"dumb"}, Reline.test_rubybin, "-I#{lib}", "-rreline", "-e", "p Reline.core.io_gate"], &:read)
-    assert_equal("Reline::GeneralIO", out.chomp)
+    assert_equal("Reline::TestDumbIO", out.chomp)
   end
 
   def get_reline_encoding