Test::Future::Deferred

Section: User Contributed Perl Documentation (3pm)
Updated: 2018-09-24
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NAME

"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;

DESCRIPTION

This subclass of Future provides two new methods and an implementation of the "await" interface, which allows the futures to appear pending at first, but then to complete when "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 "await" method, they shouldn't be mixed in the same program with other kinds of futures from real event systems or similar.

METHODS

done_later

   $f->done_later( @args )

Equivalent to invoking the regular "done" method as part of the "await" operation called on the toplevel future. This makes the future complete with the given result, but only when "get" is called.

fail_later

   $f->fail_later( $message, $category, @details )

Equivalent to invoking the regular "fail" method as part of the "await" operation called on the toplevel future. This makes the future complete with the given failure, but only when "get" is called. As the "failure" method also waits for completion of the future, then it will return the failure message given here also.

AUTHOR

Paul Evans <leonerd@leonerd.org.uk>