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PEVANS / Future-0.40 / lib / Test / Future / Deferred.pm 

            

              
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#  You may distribute under the terms of either the GNU General Public License
#  or the Artistic License (the same terms as Perl itself)
#
#  (C) Paul Evans, 2018 -- leonerd@leonerd.org.uk
package Test::Future::Deferred;
use strict;
use warnings;
use base qw( Future );
our $VERSION = '0.40';
=head1 NAME
C<Test::Future::Deferred> - a future which completes later
 my $future = Test::Future::Deferred->done_later( 1, 2, 3 );
 # Future is not ready yet
 my @result = $future->get;
=head1 DESCRIPTION
This subclass of L<Future> provides two new methods and an implementation of
the C<await> interface, which allows the futures to appear pending at first,
but then to complete when C<get> is called at the toplevel on one of them.
This behaviour is useful in unit tests to check that behaviour of a module
under test is correct even with non-immediate futures, as it allows a future
to easily be constructed that will complete "soon", but not yet, without
needing an event loop.
Because these futures provide their own C<await> method, they shouldn't be
mixed in the same program with other kinds of futures from real event systems
or similar.
=cut
my @deferrals;
sub await
{
   while( my $d = shift @deferrals ) {
      my ( $f, $method, @args ) = @$d;
      $f->$method( @args );
   }
   # TODO: detect if still not done with no more deferrals
}
=head1 METHODS
=cut
=head2 done_later
   $f->done_later( @args )
Equivalent to invoking the regular C<done> method as part of the C<await>
operation called on the toplevel future. This makes the future complete with
the given result, but only when C<get> is called.
=cut
sub done_later
{
   my $self = ref $_[0] ? shift : shift->new;
   push @deferrals, [ $self, done => @_ ];
   return $self;
}
=head2 fail_later
   $f->fail_later( $message, $category, @details )
Equivalent to invoking the regular C<fail> method as part of the C<await>
operation called on the toplevel future. This makes the future complete with
the given failure, but only when C<get> is called. As the C<failure> method
also waits for completion of the future, then it will return the failure
message given here also.
=cut
sub fail_later
{
   my $self = ref $_[0] ? shift : shift->new;
   push @deferrals, [ $self, fail => @_ ];
   return $self;
}
=head1 AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
=cut
0x55AA;