NAME

       Test::NoWarnings - Make sure you didn't emit any warnings while testing

SYNOPSIS

       For scripts that have no plan

         use Test::More 'no_plan';
         use Test::NoWarnings;

       that's it, you don't need to do anything else

       For scripts that look like

         use Test::More tests => x;

       change to

         use Test::More tests => x + 1;
         use Test::NoWarnings;

       For scripts that use done_testing, use:

         use Test::More;
         use Test::NoWarnings 'had_no_warnings';

         ... # your actual tests

         had_no_warnings;
         done_testing;

DESCRIPTION

       In general, your tests shouldn't produce warnings. This modules causes any warnings to be
       captured and stored. It automatically adds an extra test that will run when your script
       ends to check that there were no warnings. If there were any warnings, the test will give
       a "not ok" and diagnostics of where, when and what the warning was, including a stack
       trace of what was going on when the it occurred.

       If some of your tests are supposed to produce warnings then you should be capturing and
       checking them with Test::Warn, that way Test::NoWarnings will not see them and so not
       complain.

       The test is run by an "END" block in Test::NoWarnings. It will not be run when any forked
       children exit.

USAGE

       Simply by using the module, you automatically get an extra test at the end of your script
       that checks that no warnings were emitted. So just stick

         use Test::NoWarnings;

       at the top of your script and continue as normal.

       If you want more control you can invoke the test manually at any time with
       "had_no_warnings".

       The warnings your test has generated so far are stored in an array. You can look inside
       and clear this whenever you want with "warnings()" and "clear_warnings", however, if you
       are doing this sort of thing then you probably want to use Test::Warn in combination with
       Test::NoWarnings.

       If you have a test script written using done_testing and no test plan, you have to call
       "had_no_warnings" before you call done_testing.

   use vs require
       You will almost always want to do

         use Test::NoWarnings;

       If you do a "require" rather than a "use", then there will be no automatic test at the end
       of your script.

   Output
       If warning is captured during your test then the details will output as part of the
       diagnostics. You will get:

       • the number and name of the test that was executed just before the warning (if no test
         had been executed these will be 0 and '')

       • the message passed to "warn",

       • a full dump of the stack when warn was called, courtesy of the "Carp" module

       By default, all warning messages will be emitted in one block at the end of your test
       script.

   The :early pragma
       One common complaint from people using Test::NoWarnings is that all of the warnings are
       emitted in one go at the end. While this is the safest and most correct time to emit these
       diagnostics, it can make debugging these warnings difficult.

       As of Test::NoWarnings 1.04 you can provide an experimental ":early" pragma when loading
       the module to force warnings to be thrown via diag at the time that they actually occur.

         use Test::NoWarnings ':early';

       As this will cause the diag to be emitted against the previous test and not the one in
       which the warning actually occurred it is recommended that the pragma be turned on only
       for debugging and left off when not needed.

FUNCTIONS

   had_no_warnings
       This checks that there have been warnings emitted by your test scripts.  Usually you will
       not call this explicitly as it is called automatically when your script finishes.

   clear_warnings
       This will clear the array of warnings that have been captured. If the array is empty then
       a call to "had_no_warnings()" will produce a pass result.

   warnings
       This will return the array of warnings captured so far. Each element of this array is an
       object containing information about the warning. The following methods are available on
       these object.

       • $warn->getMessage

         Get the message that would been printed by the warning.

       • $warn->getCarp

         Get a stack trace of what was going on when the warning happened, this stack trace is
         just a string generated by the Carp module.

       • $warn->getTrace

         Get a stack trace object generated by the Devel::StackTrace module. This will return
         undef if Devel::StackTrace is not installed.

       • $warn->getTest

         Get the number of the test that executed before the warning was emitted.

       • $warn->getTestName

         Get the name of the test that executed before the warning was emitted.

PITFALLS

       When counting your tests for the plan, don't forget to include the test that runs
       automatically when your script ends.

       Checking for warnings is done using $SIG{__WARN__}.  If other modules use this hook, it
       can interfere with this module's operation.  For example, using the Carp::Always module
       will cause this module to always report no warnings.

SUPPORT

       Bugs should be reported via the CPAN bug tracker at

       <https://rt.cpan.org/Ticket/Create.html?Queue=Test-NoWarnings>

       For other issues, contact the author.

HISTORY

       This was previously known as Test::Warn::None

SEE ALSO

       Test::Builder, Test::Warn

AUTHORS

       Fergal Daly <fergal@esatclear.ie>

       Adam Kennedy <adamk@cpan.org>

COPYRIGHT

       Copyright 2003 - 2007 Fergal Daly.

       Some parts copyright 2010 - 2011 Adam Kennedy.

       This program is free software and comes with no warranty. It is distributed under the LGPL
       license

       See the file LICENSE included in this distribution or
       http://www.fsf.org/licenses/licenses.html.