Piers Cawley > Test-Routine-AutoClear-0.004 > Test::Routine::AutoClear

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Module Version: 0.004   Source  

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:

SEE ALSO ^

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.

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