Test2::Manual::Tooling::Testing - Tutorial on how to test your testing tools.
Testing your test tools used to be a complex and difficult prospect. The old
tools such as the Test::Tester manpage and the Test::Builder::Tester manpage were limited, and
fragile. Test2 on the other hand was designed from the very start to be easily
tested! This tutorial shows you how.
The key to making Test2 easily testable (specially when compared to
Test::Builder) is the intercept function.
use Test2::API qw/intercept/;
my $events = intercept {
ok(1, "pass");
ok(0, "fail");
diag("A diag");
};
The intercept function lets you use any test tools you want inside a codeblock.
No events or contexts generated within the intercept codeblock will have any
effect on the outside testing state. The intercept function completely
isolates the tools called within.
Note: Plugins and things that effect global API state may not be fully
isolated. intercept is intended specifically for event isolation.
The intercept function will return an arrayref containing all the events
that were generated within the codeblock. You can now make any assertions you
want about the events you expected your tools to generate.
[
bless({...}, 'Test2::Event::Ok'), # pass
bless({...}, 'Test2::Event::Ok'), # fail
bless({...}, 'Test2::Event::Diag'), # Failure diagnostics (not always a second event)
bless({...}, 'Test2::Event::Diag'), # custom 'A diag' message
]
Most test tools eventually produce one or more events. To effectively verify
the events you get from intercept you really should read up on how events work
the Test2::Manual::Anatomy::Event manpage. Once you know about events you can move on to
the next section which points you at some helpers.
This is the most recent set of tools to help you test your events. To really
understand these you should familiarize yourself with
the Test2::Manual::Anatomy::Event manpage. If you are going to be writing anything more
than the most simple of tools you should know how events work.
The the Test2::Tools::Tester manpage documentation is a good place for further reading.
The the Test2::Tools::HarnessTester manpage can export the summarize_events() tool.
This tool lets you run your event arrayref through the Test2::Harness manpage so that you
can get a pass/fail summary.
my $summary = summarize_events($events);
The summary looks like this:
{
plan => $plan_facet, # the plan event facet
pass => $bool, # true if the events result in a pass
fail => $bool, # true if the events result in a fail
errors => $error_count, # Number of error facets seen
failures => $failure_count, # Number of failing assertions seen
assertions => $assertion_count, # Total number of assertions seen
}
DEPRECATED These tools were written before the switch to faceted events.
These will still work, but are no longer the recommended way to test your
tools.
The the Test2::Tools::Compare manpage library exports a handful of extras to help test
events.
- event $TYPE => ...
-
Use in an array check against $events to check for a specific type of event
with the properties you specify.
- fail_events $TYPE => ...
-
Use when you expect a failing assertion of $TYPE. This will automatically check
that the next event following it is a diagnostics message with the default
failure text.
Note: This is outdated as a single event may now possess both the failing
assertion AND the failing text, such events will fail this test.
the Test2::Manual manpage - Primary index of the manual.
The source code repository for Test2-Manual can be found at
https://github.com/Test-More/Test2-Suite/.
- Chad Granum
-
- Chad Granum <exodist@cpan.org>Chad Granum
-
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/
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