manpagez: man pages & more
man Test2::Event(3)
Home | html | info | man
Test2::Event(3pm)      Perl Programmers Reference Guide      Test2::Event(3pm)


       Test2::Event - Base class for events


       Base class for all event objects that get passed through Test2.


           package Test2::Event::MyEvent;
           use strict;
           use warnings;

           # This will make our class an event subclass (required)
           use base 'Test2::Event';

           # Add some accessors (optional)
           # You are not obligated to use HashBase, you can use any object tool you
           # want, or roll your own accessors.
           use Test2::Util::HashBase qw/foo bar baz/;

           # Use this if you want the legacy API to be written for you, for this to
           # work you will need to implement a facet_data() method.
           use Test2::Util::Facets2Legacy;

           # Chance to initialize some defaults
           sub init {
               my $self = shift;
               # no other args in @_

               $self->set_foo('xxx') unless defined $self->foo;


           # This is the new way for events to convey data to the Test2 system
           sub facet_data {
               my $self = shift;

               # Get common facets such as 'about', 'trace' 'amnesty', and 'meta'
               my $facet_data = $self->common_facet_data();

               # Are you making an assertion?
               $facet_data->{assert} = {pass => 1, details => 'my assertion'};

               return $facet_data;



       $trace = $e->trace
           Get a snapshot of the Test2::EventFacet::Trace as it was when this
           event was generated

       $bool_or_undef = $e->related($e2)
           Check if 2 events are related. In this case related means their
           traces share a signature meaning they were created with the same
           context (or at the very least by contexts which share an id, which
           is the same thing unless someone is doing something very bad).

           This can be used to reliably link multiple events created by the
           same tool. For instance a failing test like "ok(0, "fail"" will
           generate 2 events, one being a Test2::Event::Ok, the other being a
           Test2::Event::Diag, both of these events are related having been
           created under the same context and by the same initial tool (though
           multiple tools may have been nested under the initial one).

           This will return "undef" if the relationship cannot be checked,
           which happens if either event has an incomplete or missing trace.
           This will return 0 if the traces are complete, but do not match. 1
           will be returned if there is a match.

       $e->add_amnesty({tag => $TAG, details => $DETAILS});
           This can be used to add amnesty to this event. Amnesty only effects
           failing assertions in most cases, but some formatters may display
           them for passing assertions, or even non-assertions as well.

           Amnesty will prevent a failed assertion from causing the overall
           test to fail.  In other words it marks a failure as expected and

           Note: This is how 'TODO' is implemented under the hood. TODO is
           essentially amnesty with the 'TODO' tag. The details are the reason
           for the TODO.

       $uuid = $e->uuid
           If UUID tagging is enabled (See Test::API) then any event that has
           made its way through a hub will be tagged with a UUID. A newly
           created event will not yet be tagged in most cases.

       $class = $e->load_facet($name)
           This method is used to load a facet by name (or key). It will
           attempt to load the facet class, if it succeeds it will return the
           class it loaded. If it fails it will return "undef". This caches
           the result at the class level so that future calls will be faster.

           The $name variable should be the key used to access the facet in a
           facets hashref. For instance the assertion facet has the key
           'assert', the information facet has the 'info' key, and the error
           facet has the key 'errors'. You may include or omit the 's' at the
           end of the name, the method is smart enough to try both the 's' and
           no-'s' forms, it will check what you provided first, and if that is
           not found it will add or strip the 's and try again.

       @classes = $e->FACET_TYPES()
       @classes = Test2::Event->FACET_TYPES()
           This returns a list of all facets that have been loaded using the
           "load_facet()" method. This will not return any classes that have
           not been loaded, or have been loaded directly without a call to

           Note: The core facet types are automatically loaded and populated
           in this list.

       $hashref = $e->common_facet_data();
           This can be used by subclasses to generate a starting facet data
           hashref. This will populate the hashref with the trace, meta,
           amnesty, and about facets.  These facets are nearly always produced
           the same way for all events.

       $hashref = $e->facet_data()
           If you do not override this then the default implementation will
           attempt to generate facets from the legacy API. This generation is
           limited only to what the legacy API can provide. It is recommended
           that you override this method and write out explicit facet data.

       $hashref = $e->facets()
           This takes the hashref from "facet_data()" and blesses each facet
           into the proper "Test2::EventFacet::*" subclass. If no class can be
           found for any given facet it will be passed along unchanged.

       @errors = $e->validate_facet_data();
       @errors = $e->validate_facet_data(%params);
       @errors = $e->validate_facet_data(\%facets, %params);
       @errors = Test2::Event->validate_facet_data(%params);
       @errors = Test2::Event->validate_facet_data(\%facets, %params);
           This method will validate facet data and return a list of errors.
           If no errors are found this will return an empty list.

           This can be called as an object method with no arguments, in which
           case the "facet_data()" method will be called to get the facet data
           to be validated.

           When used as an object method the "\%facet_data" argument may be

           When used as a class method the "\%facet_data" argument is

           Remaining arguments will be slurped into a %params hash.

           Currently only 1 parameter is defined:

           require_facet_class => $BOOL
               When set to true (default is false) this will reject any facets
               where a facet class cannot be found. Normally facets without
               classes are assumed to be custom and are ignored.


       Facets are how events convey their purpose to the Test2 internals and
       formatters. An event without facets will have no intentional effect on
       the overall test state, and will not be displayed at all by most
       formatters, except perhaps to say that an event of an unknown type was

       Facets are produced by the "facet_data()" subroutine, which you should
       nearly-always override. "facet_data()" is expected to return a hashref
       where each key is the facet type, and the value is either a hashref
       with the data for that facet, or an array of hashref's. Some facets
       must be defined as single hashrefs, some must be defined as an array of
       hashrefs, No facets allow both.

       "facet_data()" MUST NOT bless the data it returns, the main hashref,
       and nested facet hashref's MUST be bare, though items contained within
       each facet may be blessed. The data returned by this method should also
       be copies of the internal data in order to prevent accidental state

       "facets()" takes the data from "facet_data()" and blesses it into the
       "Test2::EventFacet::*" packages. This is rarely used however, the
       EventFacet packages are primarily for convenience and documentation.
       The EventFacet classes are not used at all internally, instead the raw
       data is used.

       Here is a list of facet types by package. The packages are not used
       internally, but are where the documentation for each type is kept.

       Note: Every single facet type has the 'details' field. This field is
       always intended for human consumption, and when provided, should
       explain the 'why' for the facet. All other fields are facet specific.

       about => {...}

           This contains information about the event itself such as the event
           package name. The "details" field for this facet is an overall
           summary of the event.

       assert => {...}

           This facet is used if an assertion was made. The "details" field of
           this facet is the description of the assertion.

       control => {...}

           This facet is used to tell the Test2::Event::Hub about special
           actions the event causes. Things like halting all testing,
           terminating the current test, etc. In this facet the "details"
           field explains why any special action was taken.

           Note: This is how bail-out is implemented.

       meta => {...}

           The meta facet contains all the meta-data attached to the event. In
           this case the "details" field has no special meaning, but may be
           present if something sets the 'details' meta-key on the event.

       parent => {...}

           This facet contains nested events and similar details for subtests.
           In this facet the "details" field will typically be the name of the

       plan => {...}

           This facet tells the system that a plan has been set. The "details"
           field of this is usually left empty, but when present explains why
           the plan is what it is, this is most useful if the plan is to skip-

       trace => {...}

           This facet contains information related to when and where the event
           was generated. This is how the test file and line number of a
           failure is known.  This facet can also help you to tell if tests
           are related.

           In this facet the "details" field overrides the "failed at
           test_file.t line 42." message provided on assertion failure.

       amnesty => [{...}, ...]

           The amnesty facet is a list instead of a single item, this is
           important as amnesty can come from multiple places at once.

           For each instance of amnesty the "details" field explains why
           amnesty was granted.

           Note: Outside of formatters amnesty only acts to forgive a failing

       errors => [{...}, ...]

           The errors facet is a list instead of a single item, any number of
           errors can be listed. In this facet "details" describes the error,
           or may contain the raw error message itself (such as an exception).
           In perl exception may be blessed objects, as such the raw data for
           this facet may contain nested items which are blessed.

           Not all errors are considered fatal, there is a "fail" field that
           must be set for an error to cause the test to fail.

           Note: This facet is unique in that the field name is 'errors' while
           the package is 'Error'. This is because this is the only facet type
           that is both a list, and has a name where the plural is not the
           same as the singular. This may cause some confusion, but I feel it
           will be less confusing than the alternative.

       info => [{...}, ...]

           The 'info' facet is a list instead of a single item, any quantity
           of extra information can be attached to an event. Some information
           may be critical diagnostics, others may be simply commentary in
           nature, this is determined by the "debug" flag.

           For this facet the "details" flag is the info itself. This info may
           be a string, or it may be a data structure to display. This is one
           of the few facet types that may contain blessed items.

       $bool = $e->causes_fail
           Returns true if this event should result in a test failure. In
           general this should be false.

       $bool = $e->increments_count
           Should be true if this event should result in a test count

           If your event needs to have extra effects on the Test2::Hub you can
           override this method.

           This is called BEFORE your event is passed to the formatter.

       $num = $e->nested
           If this event is nested inside of other events, this should be the
           depth of nesting. (This is mainly for subtests)

       $bool = $e->global
           Set this to true if your event is global, that is ALL threads and
           processes should see it no matter when or where it is generated.
           This is not a common thing to want, it is used by bail-out and
           skip_all to end testing.

       $code = $e->terminate
           This is called AFTER your event has been passed to the formatter.
           This should normally return undef, only change this if your event
           should cause the test to exit immediately.

           If you want this event to cause the test to exit you should return
           the exit code here. Exit code of 0 means exit success, any other
           integer means exit with failure.

           This is used by Test2::Event::Plan to exit 0 when the plan is
           'skip_all'. This is also used by Test2::Event:Bail to force the
           test to exit with a failure.

           This is called after the event has been sent to the formatter in
           order to ensure the event is seen and understood.

       $msg = $e->summary
           This is intended to be a human readable summary of the event. This
           should ideally only be one line long, but you can use multiple
           lines if necessary. This is intended for human consumption. You do
           not need to make it easy for machines to understand.

           The default is to simply return the event package name.

       ($count, $directive, $reason) = $e->sets_plan()
           Check if this event sets the testing plan. It will return an empty
           list if it does not. If it does set the plan it will return a list
           of 1 to 3 items in order: Expected Test Count, Test Directive,
           Reason for directive.

       $bool = $e->diagnostics
           True if the event contains diagnostics info. This is useful because
           a non-verbose harness may choose to hide events that are not in
           this category.  Some formatters may choose to send these to STDERR
           instead of STDOUT to ensure they are seen.

       $bool = $e->no_display
           False by default. This will return true on events that should not
           be displayed by formatters.

       $id = $e->in_subtest
           If the event is inside a subtest this should have the subtest ID.

       $id = $e->subtest_id
           If the event is a final subtest event, this should contain the
           subtest ID.


       This object consumes Test2::Util::ExternalMeta which provides a
       consistent way for you to attach meta-data to instances of this class.
       This is useful for tools, plugins, and other extensions.


       The source code repository for Test2 can be found at


       Chad Granum <>


       Chad Granum <>


       Copyright 2018 Chad Granum <>.

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


perl v5.28.1                      2018-11-01                 Test2::Event(3pm)

perl 5.28.1 - Generated Sun Jan 13 16:09:24 CST 2019
© 2000-2019
Individual documents may contain additional copyright information.