andy.pl

use Mojo::Base -strict, -signatures;

use Mojo::UserAgent;

my @content = (qw(this is a test));
my $iterator = sub { shift @content };

# Build a normal transaction
my $ua = Mojo::UserAgent->new;
my $tx = $ua->build_tx(GET => 'http://example.com');

# Start writing directly with a drain callback
my $drain = sub ($content) {
  my $chunk = $iterator->();
  if (length $chunk) {
    $content->write($chunk, __SUB__);
  } else {
    $content->write('');
  }
};
$tx->req->content->$drain;

# Process transaction
$tx = $ua->start($tx);