require 'stringio'
require File.expand_path('../../../spec_helper', __FILE__)

describe "StringIO#external_encoding" do
  it "gets the encoding of the underlying String" do
    io = StringIO.new
    io.set_encoding Encoding::EUC_JP
    io.external_encoding.should == Encoding::EUC_JP
  end

  ruby_version_is "2.3" do
    it "does not set the encoding of its buffer string if the string is frozen" do
      str = "foo".freeze
      enc = str.encoding
      io = StringIO.new(str)
      io.set_encoding Encoding::EUC_JP
      io.external_encoding.should == Encoding::EUC_JP
      str.encoding.should == enc
    end
  end
end