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DESCRIPTION

Raku module inspired by GitHub's Scientist (announcement).

See also: Test::Lab for a different take on the same idea.

test

SYNOPSIS

flowchart LR
    raku[$exp.run]
         -->|execute| use(Control Code)
         --> compare(Compare Result)

    raku -->|execute| try(Candidate Code)
         --> compare(Compare Result)

    use --> return[Return Result]

    compare -->|publish| Metrics
use Scientist;

my $experiment = Scientist.new(
    experiment => 'Tree',
    try => sub {return 99},
    use => sub {return 10},
);

my $answer = $experiment.run;

say "The number ten is $answer";
warn 'There was a mismatch between control and candidate'
    if $test.result{'mismatched'};

Introduction

This module is inspired by the Scientist ruby code released by GitHub under the MIT license in 2015/2016.

In February 2016 I started writing the Perl5 module to bring similar ideas to Perl. Later I started this module to apply same ideas in Raku.

Please get involved in this module; contact lancew@cpan.org with ideas, suggestions; support, etc.

This code is also released under the MIT license to match the original Ruby implementation.

Methods / Attributes

context(<HASHREF>)

Provide contextual information for the experiment; will be returned in the result set.

Should be a hashref

enabled(<TRUE>|<FALSE>)

DEFAULT : TRUE Boolean switch to enable or disable the experiment. If disabled the experiment will only return the control code (use) result. The candidate code (try) will NOT be executed. The results set will not be populated.

experiment(<STRING>)

Simply the name of the experiment included in the result set.

publish

Publish is a method called by ->run().

Scientist is design so that you create your own personalised My::Scientist module and extend publish to do what you want/need. For example push timing and mismathc information to Statsd.

use(<CODEREF>)

Control code to be included in the experiment. This code will be executed and returned when the experiment is run. NB: This code is run and returned even if experiment enabed=false.

run()

This method executes the control (use) code and if experiment enabled will also run the candidate (try) code. The control and candidate code is run in random order.

try(<CODEREF>)

Candidate code to be included in the experiment. This code will be executed and discarded when the experiment is run.

Extending Publish

To automate reporting of experiement results, you will want to write your own .publish() method. Publish is called by .run().

A typical example would be to push timing information to Statsd or a database.

use Scientist;

class MyScientist is Scientist {
    has $.test_value is rw;
    method publish {
        # Do Stuff...
    }
}

my $experiment = MyScientist.new(
    experiment => 'Tree',
    enabled => True,
    try => sub {return 99},
    use => sub {return 88},
);

AUTHOR

Lance Wicks lancew@cpan.org

COPYRIGHT AND LICENSE

This software is Copyright (c) 2016 by Lance Wicks.

This is free software, licensed under:

The MIT (X11) License

The MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

SEE ALSO

http://www.infoq.com/news/2016/02/github-scientist-refactoring

http://githubengineering.com/scientist/

https://news.ycombinator.com/item?id=11104781

https://github.com/ziyasal/scientist.js

http://tech-blog.cv-library.co.uk/2016/03/03/introducing-scientist/