Test::Exception - Test exception based code

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

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

  use Test::Exception tests => 5;

  # then...

  # Check that something died
  dies_ok {$foo->method1} 'expecting to die';

  # Check that something did not die
  lives_ok {$foo->method2} 'expecting to live';

  # Check that the stringified exception matches given regex
  throws_ok {$foo->method3} qr/division by zero/, 'zero caught okay';

  # Check an exception of the given class (or subclass) is thrown
  throws_ok {$foo->method4} 'Error::Simple', 'simple error thrown';

  # Check that a test runs without an exception
  lives_and {is $foo->method, 42} 'method is 42';

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

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

You can specify the test plan when you CWuse Test::Exception in the same way as CWuse Test::More. See Test::More for details.

dies_ok

Checks that a piece of code dies, rather than returning normally. For example:

    sub div {
        my ($a, $b) = @_;
        return( $a / $b );
    };

    dies_ok { div(1, 0) } 'divide by zero detected';

A true value is returned if the test succeeds, false otherwise. On exit $@ is guaranteed to be the cause of death (if any). The test name is optional, but recommended.

lives_ok

Checks that a piece of code exits normally, and doesn't die. For example:

    sub read_file {
        my $file = shift;
        local $/ = undef;
        open(FILE, $file) or die "open failed ($!)\n";
        $file = <FILE>;
        close(FILE);
        return($file);
    };

    my $file;
    lives_ok { $file = read_file('test.txt') } 'file read';

Should a lives_ok() test fail it produces appropriate diagnostic messages. For example:

    not ok 1 - file read
    #     Failed test (test.t at line 15)
    # died: open failed (No such file or directory)

A true value is returned if the test succeeds, false otherwise. On exit $@ is guaranteed to be the cause of death (if any). The test name is optional, but recommended.

throws_ok

Tests to see that a specific exception is thrown. throws_ok() has two forms:

  throws_ok BLOCK REGEX, TEST_NAME
  throws_ok BLOCK CLASS, TEST_NAME

In the first form the test passes if the stringified exception matches the give regular expression. For example:

    throws_ok { 
        read_file('test.txt') 
    } qr/No such file/, 'no file';

If your perl does not support CWqr// you can also pass a regex-like string, for example:

    throws_ok { 
        read_file('/etc/kcpassword') 
    } '/Permission denied/', 'no permissions';

The second form of throws_ok() test passes if the exception is of the same class as the one supplied, or a subclass of that class. For example:

    throws_ok {$foo->bar} "Error::Simple", 'simple error';

Will only pass if the CWbar method throws an Error::Simple exception, or a subclass of an Error::Simple exception. You can get the same effect by passing an instance of the exception you want to look for. The following is equivalent to the previous example:

    my $SIMPLE = Error::Simple->new();
    throws_ok {$foo->bar} $SIMPLE, 'simple error';

Should a throws_ok() test fail it produces appropriate diagnostic messages. For example:

    not ok 3 - simple error
    #     Failed test (test.t at line 48)
    # expecting: Error::Simple exception
    # found: normal exit

A true value is returned if the test succeeds, false otherwise. On exit $@ is guaranteed to be the cause of death (if any). The test name is optional. If no test name is given a description of the exception being checked for is used.

lives_and

Run a test that may throw an exception. For example, instead of doing:

    my $file;
    lives_ok { $file = read_file('answer.txt') } 'read_file worked';
    is $file, "42\n", 'answer was 42';

You can use lives_and() like this:

    lives_and { is read_file('answer.txt'), "42\n" } 'answer is 42';

Which is the same as doing

    is read_file('answer.txt'), "42\n", 'answer is 42';

unless CWread_file('answer.txt') dies, in which case you get the same kind of error as lives_ok()

    not ok 1 - answer is 42
    #     Failed test (test.t at line 15)
    # died: open failed (No such file or directory)

A true value is returned if the test succeeds, false otherwise. On exit $@ is guaranteed to be the cause of death (if any). The test name is optional, but recommended.

None known at the time of writing.

If you find any please let me know by e-mail, or report the problem with <http://rt.cpan.org/>.

Nothing at the time of writing.

If you think this module should do something that it doesn't do at the moment please let me know.

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

Thanks to Michael G Schwern, Mark Fowler, Janek Schleicher, chromatic, Mark Fowler, Peter Scott, Aristotle and Andy Lester for suggestions, bug reports and patches.

Adrian Howard <adrianh@quietstars.com>

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

Test::Builder

Support module for building test libraries.

Test::Simple & Test::More

Basic utilities for writing tests.

Test::Warn & Test::NoWarnings

Modules to help test warnings.

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

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

Copyright 2002-2004 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.