Test2::Compare::Base - Base class for comparison classes.

- NAME
- DESCRIPTION
- SYNOPSIS
- METHODS
- SOURCE
- MAINTAINERS
- AUTHORS
- COPYRIGHT

# NAME

Test2::Compare::Base - Base class for comparison classes.

# DESCRIPTION

All comparison classes for Test2::Compare should inherit from this base class.

# SYNOPSIS

    package Test2::Compare::MyCheck;
    use strict;
    use warnings;

    use base 'Test2::Compare::Base';
    use Test2::Util::HashBase qw/stuff/;

    sub name { 'STUFF' }

    sub operator {
        my $self = shift;
        my ($got) = @_;
        return 'eq';
    }

    sub verify {
        my $self = shift;
        my $params = @_;

        # Always check if $got exists! This method must return false if no
        # value at all was received.
        return 0 unless $params{exists};

        my $got = $params{got};

        # Returns true if both values match. This includes undef, 0, and other
        # false-y values!
        return $got eq $self->stuff;
    }

# METHODS

Some of these must be overridden, others can be.

$dclass = $check->delta_class

  Returns the delta subclass that should be used. By default Test2::Compare::Delta is used.

@deltas = $check->deltas(id => $id, exists => $bool, got => $got, convert => \&convert, seen => \%seen)

  Should return child deltas.

@lines = $check->got_lines($got)

  This is your chance to provide line numbers for errors in the `$got` structure.

$op = $check->operator()
$op = $check->operator($got)

  Returns the operator that was used to compare the check with the received data in `$got`. If there was no value for got then there will be no arguments, undef will only be an argument if undef was seen in `$got`. This is how you can tell the difference between a missing value and an undefined one.

$bool = $check->verify(id => $id, exists => $bool, got => $got, convert => \&convert, seen => \%seen)

  Return true if there is a shallow match, that is both items are arrayrefs, both items are the same string or same number, etc. This should not recurse, as deep checks are done in `$check->deltas()`.

$name = $check->name

  Get the name of the check.

$display = $check->render

  What should be displayed in a table for this check, usually the name or value.

$delta = $check->run(id => $id, exists => $bool, got => $got, convert => \&convert, seen => \%seen)

  This is where the checking is done, first a shallow check using `$check->verify`, then checking `$check->deltas()`. `\%seen` is used to prevent cycles.

# SOURCE

The source code repository for Test2-Suite can be found at https://github.com/Test-More/Test2-Suite/.

# MAINTAINERS

Chad Granum <exodist@cpan.org>

# AUTHORS

Chad Granum <exodist@cpan.org>

# COPYRIGHT

Copyright 2018 Chad Granum <exodist@cpan.org>.

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

See http://dev.perl.org/licenses/

Test2::Compare::Base - Base class for comparison classes.