require_relative '../../spec_helper'
require 'etc'

describe "Etc.getlogin" do
  it "returns the name associated with the current login activity" do
    getlogin_null = false

    # POSIX logname(1) shows getlogin(2)'s result
    # NOTE: Etc.getlogin returns ENV['USER'] if getlogin(2) returns NULL
    begin
      # make Etc.getlogin to return nil if getlogin(3) returns NULL
      envuser, ENV['USER'] = ENV['USER'], nil
      if Etc.getlogin
        if ENV['TRAVIS'] and platform_is(:darwin)
          # See https://travis-ci.org/ruby/spec/jobs/285967744
          # and https://travis-ci.org/ruby/spec/jobs/285999602
          Etc.getlogin.should be_an_instance_of(String)
        else
          # Etc.getlogin returns the same result of logname(2)
          # if it returns non NULL
          if system("which logname", out: File::NULL, err: File::NULL)
            Etc.getlogin.should == `logname`.chomp
          else
            # fallback to `id` command since `logname` is not available
            Etc.getlogin.should == `id -un`.chomp
          end
        end
      else
        # Etc.getlogin may return nil if the login name is not set
        # because of chroot or sudo or something.
        Etc.getlogin.should be_nil
        getlogin_null = true
      end
    ensure
      ENV['USER'] = envuser
    end

    # if getlogin(2) returns NULL, Etc.getlogin returns ENV['USER']
    if getlogin_null
      Etc.getlogin.should == ENV['USER']
    end
  end
end