NAME

Test::Deep::This - Test::Deep extension to check predicates on plain scalars

SYNOPSIS

use Test::Deep;
use Test::Deep::This
  qw(this); # exported by default actually

cmp_deeply(
  [0, 1],
  [!this, this]
); # passes: 0 is false, 1 is true.

cmp_deeply(
  [5, 9],
  [abs(this - 4) < 2, 10 - sqrt(this) < this * 2],
); # passes: abs(5 - 4) < 2 and 10 - sqrt(9) < 9 * 2.

cmp_deeply(
  { a => 1 },
  { a => 10 - sqrt(this) < this * 2 }
); # fails: 10 - sqrt(1) == 9 > 2 == 1 * 2

cmp_deeply(
  ["123"],
  [re(qr/^\d+(\d)$/, [this < 4]) & this > 100]
); # passes: 3 < 4 while 123 > 100

DESCRIPTION

Test::Deep::This module extends Test::Deep framework with a new this keyword to denote a "current" nested scalar. Standard unary and binary perl operators can be applied to this to construct some complex predicate expressions. Those predicates are completely interoperable with other Test::Deep comparison operations like re.

Some native Test::Deep comparators may be expressed via this in a somewhat native manner. For example bool(1) is just this and bool(0) is !this. num(10, 0.01) might be written as abs(this - 10) < 0.01. Any expression of this could be expressed using the Test::Deep code functor, but the later lacks proper diagnostics when the test check fails.

SEE ALSO

Test::Deep

MAINTAINER and AUTHOR

Andrei Mischchenko <me@druxa.ru>