phpman > perldoc > Test2::Event(3perl)

NAME
    Test2::Event - Base class for events

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

SYNOPSIS
        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;
        }

        1;

METHODS
  GENERAL
    $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 allowed.

        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 "load_facet()".

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

  NEW API
    $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 omitted.

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

        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.

   WHAT ARE FACETS?
    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
    seen.

    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 hashrefs. 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 hashrefs
    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
    modification.

    "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 => {...}
        Test2::EventFacet::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 => {...}
        Test2::EventFacet::Assert

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

    control => {...}
        Test2::EventFacet::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 => {...}
        Test2::EventFacet::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 => {...}
        Test2::EventFacet::Parent

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

    plan => {...}
        Test2::EventFacet::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-all.

    trace => {...}
        Test2::EventFacet::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 => [{...}, ...]
        Test2::EventFacet::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 assertion.

    errors => [{...}, ...]
        Test2::EventFacet::Error

        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 => [{...}, ...]
        Test2::EventFacet::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.

  LEGACY API
    $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 increment.

    $e->callback($hub)
        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.

THIRD PARTY META-DATA
    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.

SOURCE
    The source code repository for Test2 can be found at http://github.com/Test-More/test-more/.

MAINTAINERS
    Chad Granum <exodist AT cpan.org>

AUTHORS
    Chad Granum <exodist AT cpan.org>

COPYRIGHT
    Copyright 2020 Chad Granum <exodist AT cpan.org>.

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

    See http://dev.perl.org/licenses/