NAME

Test::Routine::AutoClear - Enables autoclearing attrs in Test::Routines

VERSION

version 0.004

SYNOPSIS

use Test::Routine::AutoClear;
use Test::More;
use File::Tempdir;

has _tempdir => (
    is        => 'ro',
    isa       => 'Int',
    builder   => '_build_tempdir',
    lazy      => 1,
    autoclear => 1,
    handles   => {
        tempdir => 'name',
    },
);

sub _build_tempdir {
    File::Tempdir->new();
}

And now all the tests that use a tempdir in your test routine will get a fresh Tempdir

DESCRIPTION

When I'm writing tests with Test::Routine I find myself writing code like this all the time:

has counter => (
    is      => ro,
    lazy    => 1,
    default => 0
    lazy    => 1,
    clearer => 'reset_counter',
);

after run_test => sub {
    shift->reset_counter;
};

And after about the first time, I got bored of doing this. So I started to fix it, and here's my first cut.

Test::Routine::AutoClear addresses this by adding a new autoclear key to the has arguments. If you set autoclear to a true value on an attribute then, after each test is run, all the autoclearing attributes will be reset.

Clearing logic

Consider the following Test::Routine:

use Test::More;
use Test::Routine::AutoClear;
use Test::Routine::Util;

has some_attrib => (
    is        => 'ro',
    default   => 10,
    lazy      => 1,
    autoclear => 1,
    clearer   => 'reset_attrib',
);

test "This should be invariant" => sub {
    my $self = shift;
    my $attrib = $self->attrib;
    $self->reset_attrib;
    is $self->attrib, $attrib;
};

run_me "Test defaults";
run_me "Test initialising", { attrib => 20 };
done_testing;

It seems to me that, in a perfect world at least, that test should pass. Which it does. Huzzah!

Passing a builder

So... you're writing a Moose object and you want the default value to be an empty arrayref. You'll have noticed that you can't write:

has queue => (
    is => 'ro',
    default => [],
);

Moose will complain vigorously. And rightly so. If you were to do:

run_me "Something", { queue => [qw(something)] }

you would rapidly discover E<why> Moose complains. So what's a poor tester to do?

Why, take advantage of the very lovely and worthwhile builder helper and write this:

run_me "This works", { queue => builder { [] } };

and Test::Routine::AutoClear will pretend that you _actually_ declared queue like so:

has queue => (
    is => 'ro',
    default => sub { [] },
);

NB: The builder routine you passed in is called just like a Moose builder method, so you get to look at the instance you're building the value for. However, right now, this builder is _not_ called lazily, so there's no guarantee that attributes that you may depend on have been intialized yet. Expect this to be fixed in a future version.

BUGS

Lots. Including, but not limited to:

• The interface is still very fluid. I make no promises about interface stability.

• I'm pretty sure that if you end up mixing in multiple roles that use this role then you'll end up clearing your attributes lots of times.

SEE ALSO

• Test::Routine

AUTHOR

Piers Cawley <pdcawley@bofh.org.uk>

COPYRIGHT AND LICENSE

This software is copyright (c) 2012 by Piers Cawley.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm Test::Routine::AutoClear

perl -MCPAN -e shell
install Test::Routine::AutoClear