Test2::Event(3) User Contributed Perl Documentation Test2::Event(3)
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 2019 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/
perl v5.16.3 2019-09-06 Test2::Event(3)
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