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

describe "File.truncate" do
  before :each do
    @name = tmp("test.txt")
    touch(@name) { |f| f.write("1234567890") }
  end

  after :each do
    rm_r @name
  end

  it "truncates a file" do
    File.size(@name).should == 10

    File.truncate(@name, 5)
    File.size(@name).should == 5

    File.open(@name, "r") do |f|
      f.read(99).should == "12345"
      f.eof?.should == true
    end
  end

  it "truncate a file size to 0" do
    File.truncate(@name, 0).should == 0
    IO.read(@name).should == ""
  end

  it "truncate a file size to 5"  do
    File.size(@name).should == 10
    File.truncate(@name, 5)
    File.size(@name).should == 5
    IO.read(@name).should == "12345"
  end

  it "truncates to a larger file size than the original file" do
    File.truncate(@name, 12)
    File.size(@name).should == 12
    IO.read(@name).should == "1234567890\000\000"
  end

  it "truncates to the same size as the original file" do
    File.truncate(@name, File.size(@name))
    File.size(@name).should == 10
    IO.read(@name).should == "1234567890"
  end

  it "raises an Errno::ENOENT if the file does not exist" do
    # TODO: missing_file
    not_existing_file = tmp("file-does-not-exist-for-sure.txt")

    # make sure it doesn't exist for real
    rm_r not_existing_file

    begin
      lambda { File.truncate(not_existing_file, 5) }.should raise_error(Errno::ENOENT)
    ensure
      rm_r not_existing_file
    end
  end

  it "raises an ArgumentError if not passed two arguments" do
    lambda { File.truncate        }.should raise_error(ArgumentError)
    lambda { File.truncate(@name) }.should raise_error(ArgumentError)
  end

  platform_is_not :netbsd, :openbsd do
    it "raises an Errno::EINVAL if the length argument is not valid" do
      lambda { File.truncate(@name, -1)  }.should raise_error(Errno::EINVAL) # May fail
    end
  end

  it "raises a TypeError if not passed a String type for the first argument" do
    lambda { File.truncate(1, 1) }.should raise_error(TypeError)
  end

  it "raises a TypeError if not passed an Integer type for the second argument" do
    lambda { File.truncate(@name, nil) }.should raise_error(TypeError)
  end

  it "accepts an object that has a #to_path method" do
    File.truncate(mock_to_path(@name), 0).should == 0
  end
end


describe "File#truncate" do
  before :each do
    @name = tmp("test.txt")
    @file = File.open @name, 'w'
    @file.write "1234567890"
    @file.flush
  end

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

  it "does not move the file write pointer to the specified byte offset" do
    @file.truncate(3)
    @file.write "abc"
    @file.close
    @name.should have_data("123\x00\x00\x00\x00\x00\x00\x00abc")
  end

  it "does not move the file read pointer to the specified byte offset" do
    File.open(@name, "r+") do |f|
      f.read(1).should == "1"
      f.truncate(0)
      f.read(1).should == nil
    end
  end

  it "truncates a file" do
    File.size(@name).should == 10

    @file.truncate(5)
    File.size(@name).should == 5
    File.open(@name, "r") do |f|
      f.read(99).should == "12345"
      f.eof?.should == true
    end
  end

  it "truncates a file size to 0" do
    @file.truncate(0).should == 0
    IO.read(@name).should == ""
  end

  it "truncates a file size to 5"  do
    File.size(@name).should == 10
    @file.truncate(5)
    File.size(@name).should == 5
    IO.read(@name).should == "12345"
  end

  it "truncates a file to a larger size than the original file" do
    @file.truncate(12)
    File.size(@name).should == 12
    IO.read(@name).should == "1234567890\000\000"
  end

  it "truncates a file to the same size as the original file" do
    @file.truncate(File.size(@name))
    File.size(@name).should == 10
    IO.read(@name).should == "1234567890"
  end

  it "raises an ArgumentError if not passed one argument" do
    lambda { @file.truncate        }.should raise_error(ArgumentError)
    lambda { @file.truncate(1) }.should_not raise_error(ArgumentError)
  end

  platform_is_not :netbsd do
    it "raises an Errno::EINVAL if the length argument is not valid" do
      lambda { @file.truncate(-1)  }.should raise_error(Errno::EINVAL) # May fail
    end
  end

  it "raises an IOError if file is closed" do
    @file.close
    @file.closed?.should == true
    lambda { @file.truncate(42) }.should raise_error(IOError)
  end

  it "raises an IOError if file is not opened for writing" do
    File.open(@name, 'r') do |file|
      lambda { file.truncate(42) }.should raise_error(IOError)
    end
  end

  it "raises a TypeError if not passed an Integer type for the for the argument" do
    lambda { @file.truncate(nil) }.should raise_error(TypeError)
  end
end
