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Test::Exception - Test exception-based code

=head1 SYNOPSIS

  use Test::More tests => 5;
  use Test::Exception;

  # or if you don't need Test::More

  use Test::Exception tests => 5;

  # then...

  # Check that the stringified exception matches given regex
  throws_ok { $foo->method } qr/division by zero/, 'zero caught okay';

  # Check an exception of the given class (or subclass) is thrown
  throws_ok { $foo->method } 'Error::Simple', 'simple error thrown';
  
  # all Test::Exceptions subroutines are guaranteed to preserve the state 
  # of $@ so you can do things like this after throws_ok and dies_ok
  like $@, 'what the stringified exception should look like';

  # Check that something died - we do not care why
  dies_ok { $foo->method } 'expecting to die';

  # Check that something did not die
  lives_ok { $foo->method } 'expecting to live';

  # Check that a test runs without an exception
  lives_and { is $foo->method, 42 } 'method is 42';
  
  # or if you don't like prototyped functions
  
  throws_ok( sub { $foo->method }, qr/division by zero/,
      'zero caught okay' );
  throws_ok( sub { $foo->method }, 'Error::Simple', 
      'simple error thrown' );
  dies_ok( sub { $foo->method }, 'expecting to die' );
  lives_ok( sub { $foo->method }, 'expecting to live' );
  lives_and( sub { is $foo->method, 42 }, 'method is 42' );


=head1 DESCRIPTION

This module provides a few convenience methods for testing exception based code. It is built with 
L<Test::Builder> and plays happily with L<Test::More> and friends.

If you are not already familiar with L<Test::More> now would be the time to go take a look.

You can specify the test plan when you C<use Test::Exception> in the same way as C<use Test::More>.
See L<Test::More> for details.

NOTE: Test::Exception only checks for exceptions. It will ignore other methods of stopping 
program execution - including exit(). If you have an exit() in evalled code Test::Exception
will not catch this with any of its testing functions.

NOTE: This module uses L<Sub::Uplevel> and relies on overriding
C<CORE::GLOBAL::caller> to hide your test blocks from the call stack.  If this
use of global overrides concerns you, the L<Test::Fatal> module offers a more
minimalist alternative.

=cut

sub _quiet_caller (;$) { ## no critic Prototypes
    my $height = $_[0];
    $height++;

    if ( CORE::caller() eq 'DB' ) {
        # passthrough the @DB::args trick
        package DB;
        if( wantarray ) {
            if ( !@_ ) {
                return (CORE::caller($height))[0..2];
            }
            else {
                # If we got here, we are within a Test::Exception test, and
                # something is producing a stacktrace. In case this is a full
                # trace (i.e. confess() ), we have to make sure that the sub
                # args are not visible. If we do not do this, and the test in
                # question is throws_ok() with a regex, it will end up matching
                # against itself in the args to throws_ok().
                #
                # While it is possible (and maybe wise), to test if we are
                # indeed running under throws_ok (by crawling the stack right
                # up from here), the old behavior of Test::Exception was to
                # simply obliterate @DB::args altogether in _quiet_caller, so
                # we are just preserving the behavior to avoid surprises
                #
                my @frame_info = CORE::caller($height);
                @DB::args = ();
                return @frame_info;
            }
        }

        # fallback if nothing above returns
        return CORE::caller($height);
    }
    else {
        if( wantarray and !@_ ) {
            return (CORE::caller($height))[0..2];
        }
        else {
            return CORE::caller($height);
        }
    }
}

sub _try_as_caller {
    my $coderef = shift;

    # local works here because Sub::Uplevel has already overridden caller
    local *CORE::GLOBAL::caller;
    { no warnings 'redefine'; *CORE::GLOBAL::caller = \&_quiet_caller; }

    eval { uplevel 3, $coderef };
    return $@;
};

local/lib/perl5/Test/Exception.pm  view on Meta::CPAN

=head1 TO DO

If you think this module should do something that it doesn't (or does something that it shouldn't) please let me know.

You can see my current to do list at L<http://adrianh.tadalist.com/lists/public/15421>, with an RSS feed of changes at L<http://adrianh.tadalist.com/lists/feed_public/15421>.


=head1 ACKNOWLEDGMENTS

Thanks to chromatic and Michael G Schwern for the excellent Test::Builder, without which this module wouldn't be possible.

Thanks to 
Adam Kennedy,
Andy Lester, 
Aristotle Pagaltzis, 
Ben Prew, 
Cees Hek,
Chris Dolan,
chromatic, 
Curt Sampson,
David Cantrell,
David Golden, 
David Tulloh,
David Wheeler, 
J. K. O'Brien,
Janek Schleicher,
Jim Keenan, 
Jos I. Boumans, 
Joshua ben Jore,
Jost Krieger,
Mark Fowler, 
Michael G Schwern, 
Nadim Khemir,
Paul McCann,
Perrin Harkins, 
Peter Rabbitson,
Peter Scott, 
Ricardo Signes,
Rob Muhlestein,
Scott R. Godin,
Steve Purkis,
Steve, 
Tim Bunce,
and various anonymous folk for comments, suggestions, bug reports and patches.

=head1 AUTHOR

Adrian Howard <adrianh@quietstars.com>

If you can spare the time, please drop me a line if you find this module useful.


=head1 SEE ALSO

=over 4

=item L<http://del.icio.us/tag/Test::Exception>

Delicious links on Test::Exception.

=item L<Test::Fatal>

A slightly different interface to testing exceptions, without overriding C<CORE::caller>.

=item L<Test::Warnings> & L<Test::Warn> & L<Test::NoWarnings>

Modules to help test warnings.

=item L<Test::Builder>

Support module for building test libraries.

=item L<Test::Simple> & L<Test::More>

Basic utilities for writing tests.

=item L<http://qa.perl.org/test-modules.html>

Overview of some of the many testing modules available on CPAN.

=item L<http://del.icio.us/tag/perl+testing>

Delicious links on perl testing.

=back


=head1 LICENCE

Copyright 2002-2007 Adrian Howard, All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

=cut

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