Manpages - Test2_Event.3perl
Table of Contents
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 returnundef
if the relationship cannot be checked, which happens if either event has an incomplete or missing trace. This will return0
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 properTest2::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.
nil
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 afail
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 thedetails
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@cpan.org>
AUTHORS
- Chad Granum <exodist@cpan.org>
COPYRIGHT
Copyright 2020 Chad Granum <exodist@cpan.org>.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.