use Test::More tests => 4;
use strict;
use warnings;
use Graph::Directed;
my $graph = new Graph::Directed;
$graph->add_edge(qw(a b));
$graph->add_edge(qw(b c));
is($graph, "a-b,b-c");
is(show_successors($graph), "a: b; b: c; c: ");
$graph->set_vertex_attribute('b','label','bla');
is($graph, "a-b,b-c");
is(show_successors($graph), "a: b; b: c; c: ");
sub show_successors {
my $graph = shift;
my @v;
foreach my $v (sort $graph->vertices()) {
push @v, "$v: " . join(" ", sort $graph->successors($v));
}
return join("; ", @v);
}