How do you test code that uses closures?

Testing code that utilizes closures in Perl can be a bit tricky due to the encapsulated state. However, it's essential to ensure that your closures behave as expected. Here, we provide an example of how to write tests for closures using the Test::More module.


            use Test::More;
            
            sub create_closure {
                my $value = shift;
                return sub {
                    return $value * 2;
                };
            }
            
            my $closure = create_closure(5);
            is($closure->(), 10, 'Closure returns double the value');
            
            $closure = create_closure(10);
            is($closure->(), 20, 'Closure returns double the value');
            
            done_testing();