Test2::Event(3perl) | Perl Programmers Reference Guide | Test2::Event(3perl) |
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; } 1;
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.
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.
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.
Note: The core facet types are automatically loaded and populated in this 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:
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 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 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.
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.
This facet is used if an assertion was made. The "details" field of this facet is the description of the assertion.
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.
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.
This facet contains nested events and similar details for subtests. In this facet the "details" field will typically be the name of the subtest.
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.
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.
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.
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.
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.
This is called BEFORE your event is passed to the formatter.
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.
The default is to simply return the event package name.
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 http://github.com/Test-More/test-more/.
Copyright 2018 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.
See http://dev.perl.org/licenses/
2020-07-21 | perl v5.28.1 |