NAME

Perl::Critic::Policy::RequireFatalWarnings - A warning nobody reads is a bug you ship.

VERSION

version 1.000

Perl::Critic::Policy::RequireFatalWarnings

use warnings; puts a line on STDERR and carries on with whatever wrong value provoked it. In a long-running program with a busy log, nobody sees it; in a script whose output is piped somewhere, nobody sees it either. The undefined value still got interpolated, and the file it named still got written to the wrong place.

use warnings;               # not ok, the run continues regardless

use warnings FATAL => 'all';   # ok, the run stops where the bug is

This does not make warn calls fatal -- an explicit warn is a message you chose to emit, and it still just prints. What becomes fatal is the categories perl raises itself: uninitialized values, numeric conversions, redefinitions, and the rest.

PROHIBITED

use warnings;
use warnings 'all';
use warnings qw{uninitialized};
# ...or no `use warnings` in the file at all

ALLOWED

use warnings FATAL => 'all';

A file that also switches categories back off for a stretch is fine; this looks for the enabling statement, not for what happens afterwards.

CONFIGURATION

equivalent_modules

Space separated list of modules that turn fatal warnings on for you, so a file using one of them is not asked for the pragma as well. Defaults to Moose Moo Mouse strictures Test2::V0.

[RequireFatalWarnings]
equivalent_modules = strictures My::Company::Policy

CAVEATS

Fatal warnings in a module other people use can turn a caller's survivable warning into a death they did not ask for. That is a real argument, and it is why this policy is not on by default anywhere but in the distributions that opt into it.

METHODS

supported_parameters

equivalent_modules, modules that enable fatal warnings on your behalf.

default_severity

SEVERITY_MEDIUM

default_themes

bugs, maintenance

applies_to

PPI::Document

violates

Standard Perl::Critic::Policy interface. Reports once per document, on the use warnings that should have been fatal, or on the first statement in the file when there is no use warnings to point at.

BUGS

Please report any bugs or feature requests on the bugtracker website https://github.com/teodesian/perl-critic-policy-requirefatalwarnings/issues

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

AUTHORS

Current Maintainers:

  • George S. Baugh <teodesian@gmail.com>

COPYRIGHT AND LICENSE

Copyright (c) 2026 Troglodyne LLC

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.