require_relative '../../spec_helper'

describe "IO#set_encoding_by_bom" do
  before :each do
    @name = tmp('io_set_encoding_by_bom.txt')
    touch(@name)
    @io = new_io(@name, 'rb')
  end

  after :each do
    @io.close unless @io.closed?
    rm_r @name
  end

  it "returns the result encoding if found BOM UTF-8 sequence" do
    File.binwrite(@name, "\u{FEFF}abc")

    @io.set_encoding_by_bom.should == Encoding::UTF_8
    @io.external_encoding.should == Encoding::UTF_8
  end

  it "returns the result encoding if found BOM UTF_16LE sequence" do
    File.binwrite(@name, "\xFF\xFEabc")

    @io.set_encoding_by_bom.should == Encoding::UTF_16LE
    @io.external_encoding.should == Encoding::UTF_16LE
  end

  it "returns the result encoding if found BOM UTF_16BE sequence" do
    File.binwrite(@name, "\xFE\xFFabc")

    @io.set_encoding_by_bom.should == Encoding::UTF_16BE
    @io.external_encoding.should == Encoding::UTF_16BE
  end

  it "returns the result encoding if found BOM UTF_32LE sequence" do
    File.binwrite(@name, "\xFF\xFE\x00\x00abc")

    @io.set_encoding_by_bom.should == Encoding::UTF_32LE
    @io.external_encoding.should == Encoding::UTF_32LE
  end

  it "returns the result encoding if found BOM UTF_32BE sequence" do
    File.binwrite(@name, "\x00\x00\xFE\xFFabc")

    @io.set_encoding_by_bom.should == Encoding::UTF_32BE
    @io.external_encoding.should == Encoding::UTF_32BE
  end

  it "returns nil if found BOM sequence not provided" do
    File.write(@name, "abc")

    @io.set_encoding_by_bom.should == nil
  end

  it 'returns exception if io not in binary mode' do
    not_binary_io = new_io(@name, 'r')

    -> { not_binary_io.set_encoding_by_bom }.should raise_error(ArgumentError, 'ASCII incompatible encoding needs binmode')
  ensure
    not_binary_io.close
  end

  it 'returns exception if encoding already set' do
    @io.set_encoding("utf-8")

    -> { @io.set_encoding_by_bom }.should raise_error(ArgumentError, 'encoding is set to UTF-8 already')
  end

  it 'returns exception if encoding conversion is already set' do
    @io.set_encoding(Encoding::UTF_8, Encoding::UTF_16BE)

    -> { @io.set_encoding_by_bom }.should raise_error(ArgumentError, 'encoding conversion is set')
  end
end