Type::Tiny » Manual » UsingWithTestMore

Type::Tiny for test suites

Test::TypeTiny

This is a module for testing that types you've defined accept and reject the values you think they should.

 should_pass($value, $type);
 should_fail($othervalue, $type);

Easy. (But yeah, I always forget whether the type goes first or second!)

There's also a function to test that subtype/supertype relationships are working okay.

 ok_subtype($type, @subtypes);

Of course you can just check a type like this:

 ok( $type->check($value) );

But the advantage of should_pass is that if the EXTENDED_TESTING environment variable is set to true, should_pass will also perform a strict check on the value, which involves climbing up the type's inheritance tree (its parent, its parent's parent, etc) to make sure the value passes all their constraints.

If a normal check and strict check differ, this is usually a problem in the inlining code somewhere.

See Test::TypeTiny for more information.

Type::Tiny as a Replacement for Test::Deep

Here's one of the examples from the Test::Deep documentation:

 my $name_re = re('^(Mr|Mrs|Miss) \w+ \w+$');
 cmp_deeply(
   $person,
   {
     Name       => $name_re,
     Phone      => re('^0d{6}$'),
     ChildNames => array_each($name_re)
   },
   "person ok"
 );

It's pretty easy to rewrite this to use Types::Standard:

 my $name = StrMatch[ qr/^(Mr|Mrs|Miss) \w+ \w+$/ ];
 should_pass(
   $person,
   Dict[
     Name         => $name,
     Phone        => StrMatch[ qr/^0d{6}$/ ],
     ChildNames   => ArrayRef[$name]
   ]
 );

There's nothing especially wrong with Test::Deep, but if you're already familiar with Type::Tiny's built-in types and you've maybe written your own type libraries too, it will save you having to switch between using two separate systems of checks.

Next Steps

Here's your next step:

  • Type::Tiny::Manual::Params

    Advanced information on Type::Params, and using Type::Tiny with other signature modules like Function::Parameters and Kavorka.