Provided by: libtest-simple-perl_1.302167-1_all bug


       Test2::API::Stack - Object to manage a stack of Test2::Hub instances.


       The internals of this package are subject to change at any time! The public methods
       provided will not change in backwards incompatible ways, but the underlying implementation
       details might. Do not break encapsulation here!


       This module is used to represent and manage a stack of Test2::Hub objects. Hubs are
       usually in a stack so that you can push a new hub into place that can intercept and handle
       events differently than the primary hub.


           my $stack = Test2::API::Stack->new;
           my $hub = $stack->top;


       $stack = Test2::API::Stack->new()
           This will create a new empty stack instance. All arguments are ignored.

       $hub = $stack->new_hub()
       $hub = $stack->new_hub(%params)
       $hub = $stack->new_hub(%params, class => $class)
           This will generate a new hub and push it to the top of the stack. Optionally you can
           provide arguments that will be passed into the constructor for the Test2::Hub object.

           If you specify the "'class' => $class" argument, the new hub will be an instance of
           the specified class.

           Unless your parameters specify 'formatter' or 'ipc' arguments, the formatter and IPC
           instance will be inherited from the current top hub. You can set the parameters to
           "undef" to avoid having a formatter or IPC instance.

           If there is no top hub, and you do not ask to leave IPC and formatter undef, then a
           new formatter will be created, and the IPC instance from Test2::API will be used.

       $hub = $stack->top()
           This will return the top hub from the stack. If there is no top hub yet this will
           create it.

       $hub = $stack->peek()
           This will return the top hub from the stack. If there is no top hub yet this will
           return undef.

           This will call "$hub->cull" on all hubs in the stack.

       @hubs = $stack->all
           This will return all the hubs in the stack as a list.

           This will completely remove all hubs from the stack. Normally you do not want to do
           this, but there are a few valid reasons for it.

           This will push the new hub onto the stack.

           This will pop a hub from the stack, if the hub at the top of the stack does not match
           the hub you expect (passed in as an argument) it will throw an exception.


       The source code repository for Test2 can be found at


       Chad Granum <>


       Chad Granum <>


       Copyright 2019 Chad Granum <>.

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.