On 5/28/2013 9:47 PM, Russel Winder wrote:
> Looks like I am out of luck then. :-(
Not at all.
> The context is writing a small program that can be a filter or operate
> on files: actually it is the wc program. So it needs to work with opened
> files and stdin. That is fine (sort of). The issue comes when writing
> unit tests for the code: unit tests should not touch the file system, so
> I need a memory buffer backed std.stdio.File for the tests. A mock file
> in a sense.As noted earlier Go, Python, all JVM languages have such
> things, and it really needs to be part of D. If there really is nothing
> like this, I should add a JIRA issue and see if I can create a pull
> request later in the summer.
Coincidentally, I wrote a wc program a year ago:
-------------------------
import std.stdio, std.file, std.string, std.array, std.algorithm, std.typecons;
import lazysplit;
alias Tuple!(int, "lines", int, "words", int, "chars") Lwc;
void main(string[] args) {
writeln(" lines words bytes file");
auto total = args[1 .. args.length].wctotal();
if (args.length > 2)
writefln("--------------------------------------\n%8s%8s%8s total",
total[0..3]);
}
auto wctotal(R)(R args) {
Lwc total;
foreach (arg; args) {
auto t = arg.File().byLine(KeepTerminator.yes).wc();
writefln("%8s%8s%8s %s", t[0..3], arg);
foreach(i, v; t)
total[i] += v;
}
return total;
}
auto wc(R)(R r) {
Lwc t;
foreach (line; r) {
t.lines += 1;
t.words += line.lazySplit().count();
t.chars += line.length;
}
return t;
}
--------------------------------------
Just replace "arg.File().byLine(KeepTerminator.yes)" with a string filled with
your mocked data.