Tempfiles in unittests

[Magnus Lie Hetland]

I'm testing a class that writes various things to a file, and I'd like 
to test that behavior, and I'm wondering what the standard solution 
here is.

In Python, I'd just use a StringIO class, for example. It seems sort of 
impractical to make std.outbuffer to work as a File (even if the 
file-like parameter is a template parameter, the outbuffer methods 
don't work like the File methods, as far as I can see), so I've 
concluded that using std.stdio.tmpfile is the way to go.

However, when I'm done with the tempfile, I'd like to have its contents 
as a string. It seems that File has no method for reading the entire 
file contents into a string, so I'd have to read and concatenate lines 
or chunks or something? Now, if the File returned by tmpfile had a 
name, I could use std.file.readText(). But no such luck (as far as I 
can see, tmpfile().name is null).

So I'm just wondering -- what's "the way" to do this sort of testing? 
And if it is along the lines of what I'm doing, is there some 
function/method for reading the contents of a File as a string?

(I guess this goes for much file-related functionality; much of it 
seems to be very related to file-names and actual files, rather than 
"file-like" objects, i.e., those with the appropriate methods...)

-- 
Magnus Lie Hetland
http://hetland.org