ruby--ruby/spec/ruby/core/io/syswrite_spec.rb

require_relative '../../spec_helper'
require_relative 'fixtures/classes'
require_relative 'shared/write'

describe "IO#syswrite on a file" do
  before :each do
    @filename = tmp("IO_syswrite_file") + $$.to_s
    File.open(@filename, "w") do |file|
      file.syswrite("012345678901234567890123456789")
    end
    @file = File.open(@filename, "r+")
    @readonly_file = File.open(@filename)
  end

  after :each do
    @file.close
    @readonly_file.close
    rm_r @filename
  end

  it "writes all of the string's bytes but does not buffer them" do
    written = @file.syswrite("abcde")
    written.should == 5
    File.open(@filename) do |file|
      file.sysread(10).should == "abcde56789"
      file.seek(0)
      @file.fsync
      file.sysread(10).should == "abcde56789"
    end
  end

  it "warns if called immediately after a buffered IO#write" do
    @file.write("abcde")
    lambda { @file.syswrite("fghij") }.should complain(/syswrite/)
  end

  it "does not warn if called after IO#write with intervening IO#sysread" do
    @file.syswrite("abcde")
    @file.sysread(5)
    lambda { @file.syswrite("fghij") }.should_not complain
  end

  it "writes to the actual file position when called after buffered IO#read" do
    @file.read(5)
    @file.syswrite("abcde")
    File.open(@filename) do |file|
      file.sysread(10).should == "01234abcde"
    end
  end
end

describe "IO#syswrite on a pipe" do
  it "returns the written bytes if the fd is in nonblock mode and write would block" do
    require 'io/nonblock'
    r, w = IO.pipe
    begin
      w.nonblock = true
      larger_than_pipe_capacity = 100 * 1024
      written = w.syswrite("a"*larger_than_pipe_capacity)
      written.should > 0
      written.should < larger_than_pipe_capacity
    ensure
      w.close
      r.close
    end
  end
end

describe "IO#syswrite" do
  it_behaves_like :io_write, :syswrite
end