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

# -*- encoding: utf-8 -*-
require_relative '../../spec_helper'

ruby_version_is "2.5" do
  platform_is_not :windows do
    describe "IO#pwrite" do
      before :each do
        @fname = tmp("io_pwrite.txt")
        @file = File.open(@fname, "w+")
      end

      after :each do
        @file.close
        rm_r @fname
      end

      it "returns the number of bytes written" do
        @file.pwrite("foo", 0).should == 3
      end

      it "accepts a string and an offset"  do
        @file.pwrite("foo", 2)
        @file.pread(3, 2).should == "foo"
      end

      it "does not advance the pointer in the file" do
        @file.pwrite("bar", 3)
        @file.write("foo")
        @file.pread(6, 0).should == "foobar"
      end

      it "raises IOError when file is not open in write mode" do
        File.open(@fname, "r") do |file|
          lambda { file.pwrite("foo", 1) }.should raise_error(IOError)
        end
      end

      it "raises IOError when file is closed" do
        file = File.open(@fname, "w+")
        file.close
        lambda { file.pwrite("foo", 1) }.should raise_error(IOError)
      end
    end
  end
end