Fennec - A test helper providing RSPEC, Workflows, Parallelization, and Encapsulation.


Fennec started as a project to improve the state of testing in Perl. Fennec looks to existing solutions for most problems, so long as the existing solutions help meet the features listed below.


Fennec versions below 1.000 were considered experimental, and the API was subject to change. As of version 1.0 the API is considered stabalized. New versions may add functionality, but not remove or significantly alter existing functionality.


Forking Works

Forking in tests just plain works. You can fork, and run assertions (tests) in both processes.

Test groups can be run alone

Encapsulated test groups can be run individually, without running the entire file. (See Test::Workflow)

Parallelization within test files

Encapsulated test groups can be run in parallel if desired. (On by default with up to 3 processes)

Test reordering

Tests groups can be sorted, randomized, or sorted via a custom method. (see Test::Workflow)

Test::Builder and Test::Builder2 compatibility

Fennec is compatible with Test::Builder based tools. Test::Builder2 support is in-place, but experimental until Test::Builder2 is officially released.

Ability to decouple from Test::Builder

Fennec is configurable to work on alternatives to Test::Builder.

No need to formally end tests

You do not need to put anything such as done_testing() at the end of your test file.

Test counting is handled for you

You do not need to worry about test counts.

Diagnostic messages are grouped with the failed test

Annoyed when your test failure and the diagnostics messages about that test are decoupled?

    ok 1 - foo
    ok 2 - bar
    not ok 3 - baz
    ok 4 - bannana
    ok 5 - pear
    # Test failure on line 67
    # expected: 'baz'
    #      got: 'bazz'

This happens because normal output is sent to STDOUT, while errors are sent to STDERR. This is important in a non-verbose harness so that you can still see error messages. In a verbose harness however it is just plain annoying. Fennec checks the verbosity of the harness, and sends diagnostic messages to STDOUT when the harness is verbose.

Note: This is not IO redirection or handle manipulation, your warnings and errors will still go to STDERR.


    package MyTest;
    use strict;
    use warnings;
    use Fennec;

    tests foo => sub {
        ok( 1, 'bar' );

    tests another => sub {
        ok( 1, 'something passed' );

    tests not_ready => (
        todo => "Feature not implemented",
        code => sub { ... },

    tests very_not_ready => (
        skip => "These tests will die if run"
        code => sub { ... },


By default these test groups will be run in parallel. They will also be run in random order by default. See the "CONFIGURATION" for more details on controlling behavior. Also see Test::Workflow for more useful and poweful test groups and structures.


If you use Fennec::Declare you can write tests like this:

    package MyTest;
    use strict;
    use warnings;
    use Fennec;

    tests foo {
        ok( 1, 'bar' );


Thats right, no => sub and no trailing ';'.


     1: package MyTest;
     2: use strict;
     3: use warnings;
     4: use Fennec;
     6: tests foo => sub {
     7:     ok( 1, 'bar' );
     8: };
    10: tests another => sub {
    11:    ok( 1, 'something passed' );
    12: };
    14: 1;

In the above code there are 2 test groups, 'foo', and 'another'. If you wanted, you could run just one, without the others running. Fennec looks at the 'FENNEC_TEST' environment variable. If the variable is set to a string, then only the test groups with that string as a name will run.

    $ FENNEC_TEST="foo" prove -Ilib -v t/FennecTest.t

In addition, you could provide a line number, and only the test group defined across that line will be run. For example, to run 'foo' you could give the line number 6, 7 or 8 to run that group alone.

    $ FENNEC_TEST="7" prove -Ilib -v t/FennecTest.t

This will run only test 'foo'. The use of line numbers makes editor integration very easy. Most editors will let you bind a key to running the above command replacing t/FennecTest.t with the current file, and automatically inserting the current line into FENNEC_TEST.



Insert this into your .vimrc file to bind the F8 key to running the current test in the current file:

    function! RunFennecLine()
        let cur_line = line(".")
        exe "!FENNEC_TEST='" . cur_line . "' prove -v -I lib %"

    " Go to command mode, save the file, run the current test
    :map <F8> <ESC>:w<cr>:call RunFennecLine()<cr>
    :imap <F8> <ESC>:w<cr>:call RunFennecLine()<cr>



The standard perl test library.


One of the more useful test libraries, used to test code that throws exceptions (dies).


Test code that issues warnings.


Provides RSPEC, and several other workflow related helpers. Also provides the test group encapsulation.


Quick and effective mocking with no action at a distance side effects.



A Fennec class can also be a Test::Class class.


If Fennec did not support this who would use it?


There is currently experimental support for Test::Builder2. Once Test::Builder2 is officially released, support will be finalized.


There are 2 ways to configure Fennec. One is to specify configuration options at import. The other is to subclass Fennec and override the defaults() method.

Configuration options:

utils => [ qw/ModuleA ModuleB .../ ]

Provide a list of modules to load. They will be imported as if you typed use MODULE.

You can specify arguments for each class like so:

    use Fennec utils => [ 'My::Util' ],
          'My::Util' => [ 'Arg1', 'Arg2' ];

parallel => $MAX

Specify the maximum number of processes Fennec should use to run your tests. Set to 0 to never create a new process. Depedning on conditions 1 MAY fork for test groups while still only running 1 at a time, but this behavior is not guarenteed.

Default: 3

runner_class => $CLASS

Specify the runner class. Default: Fennec::Runner

with_tests => \@CLASSES

Load test_groups and workflows from another class. This allows you to put test groups common to many test files into a single place for re-use.

test_sort => $SORT

This sets the test sorting method for Test::Workflow test groups. Accepts 'random', 'sort', a codeblock, or 'ordered'. This uses a fuzzy matching, you can use the shorter versions 'rand', and 'ord'.

Defaults to: 'rand'


Will shuffle the order. Keep in mind Fennec sets the random seed using the date so that tests will be determinate on the day you write them, but random over time.


Sort the test groups by name. When multiple tests are wrapped in before_all or after_all the describe/cases block name will be used.


Use the order in which the test groups were defined.

sub { my @tests = @_; ...; return @new_tests }

Specify a custom method of sorting. This is not the typical sort {} block, $a and $b will not be set.


    use Fennec parallel => 5,
                  utils => [ 'My::Util' ],
                  ... Other Options ...;


    package My::Fennec;
    use base 'Fennec';

    sub defaults {(
        utils => [qw/
            Test::More Test::Warn Test::Exception Test::Workflow
        utils_with_args => {
            My::Util => [qw/function_x function_y/],
        parallel => 5,
        runner_class => 'Fennec::Runner',

    # Hook, called after import
    sub init {
        my $class = shift;
        # All parameters passed to import(), as well as caller => [...] and meta => $meta
        my %params = @_;




This is a more complete example than that which is given in the synopsis. Most of this actually comes from Method::Workflow, See those docs for more details. Significant sections are in seperate headers, but all examples should be considered part of the same long test file.

NOTE: All blocks, including setup/teardown are methods, you can shift @_ to get $self.


    package MyTest;
    use strict;
    use warnings;
    use Fennec parallel   => 2,
               with_tests => [qw/ Test::TemplateA Test::TemplateB /],
               test_sort  => 'rand';

    # Tests can be at the package level
    use_ok( 'MyClass' );

    # Fennec works with Test::Class
    use base 'Test::Class';

    sub tc_test : Test(1) {
        my $self = shift;
        ok( 1, 'This is a Test::Class test' );

    tests loner => sub {
        my $self = shift;
        ok( 1, "1 is the loneliest number... " );

    tests not_ready => (
        todo => "Feature not implemented",
        code => sub { ... },

    tests very_not_ready => (
        skip => "These tests will die if run"
        code => sub { ... },


Here setup/teardown methods are declared in the order in which they are run, but they can really be declared anywhere within the describe block and the behavior will be identical.

    describe example => sub {
        my $self = shift;
        my $number = 0;
        my $letter = 'A';

        before_all setup => sub { $number = 1 };

        before_each letter_up => sub { $letter++ };

        # it() is an alias for tests()
        it check => sub {
            my $self = shift;
            is( $letter, 'B', "Letter was incremented" );
            is( $number, 2,   "number was incremented" );

        after_each reset => sub { $number = 1 };

        after_all teardown => sub {
            is( $number, 1, "number is back to 1" );

        describe nested => sub {
            # This nested describe block will inherit before_each and
            # after_each from the parent block.

        describe maybe_later => (
            todo => "We might get to this",
            code => { ... },


Fennec add's to the RSPEC toolset with the around keyword.

    describe addon => sub {
        my $self = shift;

        around_each localize_env => sub {
            my $self = shift;
            my ( $inner ) = @_;

            local %ENV = ( %ENV, foo => 'bar' );


        tests foo => sub {
            is( $ENV{foo}, 'bar', "in the localized environment" );


Cases are used when you have a test that you wish to run under several r tests conditions. The following is a trivial example. Each test will be run once under each case. Beware! this will run (cases x tests), with many tests and cases this can be a huge set of actual tests. In this example 8 in total will be run.

Note: The 'cases' keyword is an alias to describe. case blocks can go into any workflow and will work as expected.

    cases check_several_numbers => sub {
        my $number;
        case one => sub { $number = 2 };
        case one => sub { $number = 4 };
        case one => sub { $number = 6 };
        case one => sub { $number = 8 };

        tests is_even => sub {
            ok( !$number % 2, "number is even" );

        tests only_digits => sub {
            like( $number, qr/^\d+$/i, "number is all digits" );



Mock::Quick is imported by default. Mock::Quick is a powerful mocking library with a very friendly syntax.


    use Mock::Quick;

    my $obj = obj(
        foo => 'bar',            # define attribute
        do_it => qmeth { ... },  # define method

    is( $obj->foo, 'bar' );
    $obj->foo( 'baz' );
    is( $obj->foo, 'baz' );


    # define the new attribute automatically
    $obj->bar( 'xxx' );

    # define a new method on the fly
    $obj->baz( qmeth { ... });

    # remove an attribute or method
    $obj->baz( qclear() );


    use Mock::Quick;

    my $control = qclass(
        # Insert a generic new() method (blessed hash)
        -with_new => 1,

        # Inheritance
        -subclass => 'Some::Class',
        # Can also do
        -subclass => [ 'Class::A', 'Class::B' ],

        # generic get/set attribute methods.
        -attributes => [ qw/a b c d/ ],

        # Method that simply returns a value.
        simple => 'value',

        # Custom method.
        method => sub { ... },

    my $obj = $control->packahe->new;

    # Override a method
    $control->override( foo => sub { ... });

    # Restore it to the original
    $control->restore( 'foo' );

    # Remove the anonymous namespace we created.


    use Mock::Quick;

    my $control = qtakeover( 'Some::Package' );

    # Override a method
    $control->override( foo => sub { ... });

    # Restore it to the original
    $control->restore( 'foo' );

    # Destroy the control object and completely restore the original class Some::Package.
    $control = undef;


Mock-Quick uses Exporter::Declare. This allows for exports to be prefixed or renamed. See "RENAMING IMPORTED ITEMS" in Exporter::Declare for more information.

$obj = qobj( attribute => value, ... )

Create an object. Every possible attribute works fine as a get/set accessor. You can define other methods using qmeth {...} and assigning that to an attribute. You can clear a method using qclear() as an argument.

See Mock::Quick::Object for more.

$control = qclass( -config => ..., name => $value || sub { ... }, ... )

Define an anonymous package with the desired methods and specifications.

See Mock::Quick::Class for more.

$control = qtakeover( $package )

Take control over an existing class.

See Mock::Quick::Class for more.


Returns a special reference that when used as an argument, will cause Mock::Quick::Object methods to be cleared.

qmeth { my $self = shift; ... }

Define a method for an Mock::Quick::Object instance.






When you use Fennec, it will check to see if you called the file directly. If you directly called the file Fennec will restart Perl and run your test through Fennec::Runner.


When running a test group by line, Fennec takes it's best guess at which group the line number represents. There are 2 ways to get the line number of a codeblock:

The first is to use the B module. The B module will return the line of the first statement within the codeblock.

The other is to define the codeblock in a function call, such as tests foo => sub {...}, tests() can then use caller() which will return the last line of the statement.

Combining these methods, we can get the approximate starting and ending lines for codeblocks defined through Fennec's keywords.

This will break if you do something like:

    tests foo => \&my_test;
    sub my_test { ... }

But might work just fine if you do:

    tests foo => \&my_test;
    sub my_test { ... }

But might run both tests in this case when asking to run 'baz' by line number:

    tests foo => \&my_test;
    tests baz => sub {... }
    sub my_test { ... }


Chad Granum


Copyright (C) 2011 Chad Granum

Fennec is free software; Standard perl licence.

Fennec is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the license for more details.