use warnings;
use strict;
use Test::More;

my $re = qr{ \b type = "([^"]+)"
	(?: (?!<\w+TagIwant\b) . )* <(\w+TagIwant\b)? }msx;

is_deeply [
	q{ <blah1 phase="2" type="MyType" more_keys="Values" <Unwanted/>  <SomeTagIwant><k1="v1"></SomeTagIwant> }
		=~$re], ['MyType','SomeTagIwant'];
is_deeply [
	q{ <blah1 phase="2" type="MyType" more_keys="Values" <Unwanted/>  <SomeTagIwant/> }
		=~$re], ['MyType','SomeTagIwant'];
is_deeply [
	q{ <blah1 phase="2" type="MyType" more_keys="Values" <Unwanted/>  <SomeTagIwant k3="v3" /> }
		=~$re], ['MyType','SomeTagIwant'];
is_deeply [
	q{ <blah1 phase="2" type="MyType" more_keys="Values" <Unwanted/>}
		=~$re], ['MyType',undef];

done_testing;