Test::ExpectAndCheck::Future - expect/check-style unit testing with Future-returning methods


   use Test::More;
   use Test::ExpectAndCheck::Future;

   use Future::AsyncAwait;

   my ( $controller, $mock ) = Test::ExpectAndCheck::Future->create;

      $controller->expect( act => 123, 45 )
         ->will_done( 678 );

      is( await $mock->act( 123, 45 ), 678, '$mock->act yields result' );

      $controller->check_and_clear( '->act' );



This package creates objects that assist in writing unit tests with mocked object instances. Each mocked instance will expect to receive a given list of method calls. Each method call is checked that it received the right arguments, and will return a Future instance to yield the prescribed result. At the end of each test, each object is checked to ensure all the expected methods were called.

It is a variation of Test::ExpectAndCheck, assistance around the results of invoked methods. Every invoked method will return a Future instance. The "will_done" or "will_fail" method can then set the desired eventual result of that future instance for each expectation.

These return instances are implemented using Test::Future::Deferred, so they are not immediately ready. Instead they will only become ready after a toplevel await expression or call to the get method. This should help unit tests to run similarly to real-world behaviour, where most futures returned by real-world interfaces (such as IO systems) would not be immediately ready. This behaviour can be switched off for individual expectations by using the "immediately" method.



   $exp->will_done( @result );

Since version 0.04.

Sets that method call will return a Future instance which will succeed with the given result.


   $exp->will_fail( $message, $category, @more );

Since version 0.04.

Sets that method call will return a Future instance which will fail with the given message, and optionally category name and extra details.


   $exp->will_done( ... )->immediately;

   $exp->will_fail( ... )->immediately;

Since version 0.02.

Switches this expectation to return an immediate future, rather than a deferred one.



Since version 0.03.

Sets that the future returned by this method will not complete and simply remain pending.


   $exp->will_also_later( sub { ... } );

Since version 0.04.

Adds extra code which will run when the expected method is called, after the returned future has completed. This is performed by the use of Test::Future::Deferred.

When invoked, the code body is invoked in void context with no additional arguments.


Paul Evans <>