From: Joe Van Dyk <joevandyk@...>
Date: 2005-08-27T06:50:32+09:00
Subject: Re: stringio as file

On 8/26/05, Joe Van Dyk <joevandyk@gmail.com> wrote:
> On 8/26/05, Joe Van Dyk <joevandyk@gmail.com> wrote:
> > On 8/26/05, Joe Van Dyk <joevandyk@gmail.com> wrote:
> > > StringIO can be used as a standin for a File object when testing, right?
> > >
> > > require 'stringio'
> > >
> > > def expects_file file
> > >   file.open
> > >   puts file.gets
> > > end
> > >
> > > s = StringIO.new "Hello World\nHow are you?"
> > > expects_file s
> > >
> > > What don't I understand here?
> >
> > Ah, nevermind.  I forgot File.open is a class method.
> 
> This still confuses me though:
> 
> require 'stringio'
> 
> a = StringIO.new
> a << "Hello\n"
> a << "World"
> 
> puts a.gets   # prints nil

And further confusion:

require 'stringio'

a = StringIO.new
a << "Hello\n"
a << "World"
puts "a: #{ a.gets }"     

b = StringIO.new "Hello\nWorld"
puts "b: #{ b.gets }"

Results in:
a:
b: Hello
         
So it appears that StringIO#<< isn't doing what I think it should be
doing.  There's not much documentation on that method at ruby-doc.org
or in the Pickaxe2 book.