The Perl Toolchain Summit needs more sponsors. If your company depends on Perl, please support this very important event.
NAME
    Test::NoWarnings - Make sure you didn't emit any warnings while testing

SYNOPSIS
    For scripts that have 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;

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 warings, 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.

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:

    o 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 '')

    o the message passed to "warn",

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

EXPORTABLE 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.

BUGS
    None that I know of.

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

SEE ALSO
    Test::Builder, Test::Warn

AUTHOR
    Written by Fergal Daly <fergal@esatclear.ie>.

COPYRIGHT
    Copyright 2003 by Fergal Daly <fergal@esatclear.ie>.

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

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