Intermediate Perl Testing
(or, Let’s Not Make A Mess Of Things, Shall We?)
Josh Heumann

Have you seen these tests?
is_deeply(
get_recipes(),
[qw/ lemon_curd pancakes enchiladas /],
‘all of the recipes are there’
);
SKIP: {
skip ‘No ingredients’, 2, if @ingredients < 1;
is( $number, 23, ‘and the number is 23’ );
};
dies_ok(
sub { eat_cake },
qr/Cake isn’t chocolate/,
‘only eat chocolate cake’
);

What this talk will do

What this talk won’t do

Why
Have
Altercations
That
Encourage
Violent
Excitable
Rants?

Why
Have
Altercations
That
Encourage
Violent
Excitable
Rants?

Make them easy to run

Run early, run often

Blackbox testing

Blackbox testing

Blackbox testing

Glassbox testing

Whatever.

Testing scripts
#!/usr/bin/perl
use strict;
use warnings;
get_jiggy();
sub get_jiggy {
# details, details
}

Testing scripts
__FILE__

Testing scripts
__FILE__
.pl
gy
g
ji
t_
ge
in/
b

Testing scripts
$0

Testing scripts
$0
AKA $PROGRAM_NAME

Testing scripts
$0
AKA $PROGRAM_NAME
pl
y.
g
jig
_
et
/g
in
b

Testing scripts
$0
AKA $PROGRAM_NAME
psl.t
.
ys
ge
jggin
i
ig
j_
et
t_
es g
/bin/
t
t

Testing scripts
$0 __FILE__
!=
<>
s.tne .pl
es ≠
in gy
igg g
ji
j t_
t_ ge
es
t in/
t/ b

Testing scripts
$0 __FILE__
eq
==
.pl
gy .pl
g
ji gy
t_ g
ji
ge t_
in/ ge
b in/
b

Testing scripts
#!/usr/bin/perl
use strict;
use warnings;
get_jiggy() if $0 eq __FILE__;
sub get_jiggy {
# details, details
}

Testing scripts
#!/usr/bin/perl
use strict;
use warnings;
use Test::More tests => 42;
require_ok( ‘bin/get_jiggy.pl’ );
can_ok( ‘main’, ‘get_jiggy’, ‘jigginess achieved’ );
# test the details

Code coverage

Code coverage
cover -test

Code coverage
cover -test
./Build testcover

Code coverage
cover -test
./Build testcover
HARNESS_PERL_SWITCHES=-MDevel::Cover make test

Demonstration time!

Version control

Version control

Version control

Testing and version control
?

Testing and version control

Testing and version control

Testing and version control

Testing and version control

Testing and version control

Testing and version control

Testing and version control

Testing and version control

Testing and version control

Testing and version control

Testing and version control

Version control

Reusing test code

Reusing test code
for(qw/ is_hilarious is_annoying is_bewildering /) {
can_ok( Child, $_ );
is( Child->$_, 1, “...and the child $_” );
}

Reusing test code
sub _test_accessor {
my ( $method ) = @_;
my $getter = \"get_$method\";
my $setter = \"set_$method\";
can_ok( 'Cat', $getter );
can_ok( 'Cat', $setter );
is( Cat->new->$getter, undef, \"...and $method is
undef to start with\" );
....
}
_test_accessor( ‘sleep’ );

Reusing test code
sub _test_accessor {
my ( $method ) = @_;
my $getter = \"get_$method\";
my $setter = \"set_$method\";
can_ok( 'Cat', $getter );
can_ok( 'Cat', $setter );
is( Cat->new->$getter, undef, \"...and $method is
undef to start with\" );
....
}
_test_accessor( $_ ) for(qw/ sleep eat purr /);

Whatever.

Custom test libraries

Custom test libraries
$ prove t
t/00_basics....ok
All tests successful.
Files=1, Tests=377, 1 wallclock secs ( 0.17 cusr +
0.02 csys = 0.19 CPU)

Custom test libraries
package Test::Clowns;
use Test::Builder;
use Perl6::Junction qw/ any /;
my $Test = Test::Builder->new;
sub test_clowns {
my($clown, $name) = @_;
$clown->hop_out_of_a_very_small_car();
$Test->ok( $clown->can_juggle, $name );
$Test->ok( $clown->has_pies, $name );
if( any($clown->faces) eq ‘scary’ ) {
$Test->fail( “clowns shouldn’t be scary” );
}
$Test->ok( $clown->is_scary, $name );
}

Custom test libraries
use TAP::Harness;
my $harness = TAP::Harness->new(
verbose => 1,
lib => [ 'lib', 'blib/lib' ],
);
$harness->runtests(@tests);
+

Fixtures

our %clients = (
1001 => {
client_id => 1001,
dob => '1926-05-25',
fname => 'Miles',
lname => 'Davis',
sex => 'Male',
race => 'Black',
marital_status => 'Divorced',
substance_abuse => 'Yes',
alcohol_abuse => 'Yes',
gambling_abuse => 'Unknown',
religion => 'Muslim',
},

1002 => {
client_id => 1002,
dob => '1922-04-21',
fname => 'Charles',
lname => 'Mingus',
sex => 'Male',
race => 'Other',
marital_status => 'Married',
substance_abuse => 'No',
alcohol_abuse => 'Yes',
gambling_abuse => 'Unknown',
religion => 'Buddhist',
},
# etc,
# etc,
# etc.
);

for my $client_id (keys %clients) {
Test::Client->new(
id => $clients{ $client_id }
)->save;
}

for my $client_id (keys %clients) {
Test::Client->new(
id => $clients{ $client_id }
)->save;
}
Test::Client->new(1001)->save;

sub create_test_client {
Test::Client->new( %args )->save;
}
create_test_client(
id => 2,
dob => undef,
);

sub create_test_client {
$args{ dob } ||= ‘1970-01-01’;
Test::Client->new( %args )->save;
}
create_test_client(
id => 2,
dob => undef,
);

sub create_test_client {
$args{ dob } ||= ‘1970-01-01’;
$args{ shrink } ||= create_test_shrink;
Test::Client->new( %args )->save;
}
create_test_client(
id => 2,
dob => undef,
);

Mocking

Mocking

Mocking
Test::MockObject

Mocking
Test::MockObject
Test::MockClass

Mocking
Test::MockObject
Test::MockClass
Sub::Override

Mocking
Test::MockDBI
Test::Mock::LWP
Test::Mock::HTTP::Request
Test::Mock::HTTP::Response

Selenium

How to
win friends
and
convince
others to
test

Speeding up tests

Where to start?

Review

Review
Make your tests easy to run

Review
Make your tests easy to run
Run them often

Review
Make your tests easy to run
Run them often
Test your modules

Review
Make your tests easy to run
Run them often
Test your modules
Test your scripts

Review
Make your tests easy to run
Run them often
Test your modules
Test your scripts
Improve your code coverage with Devel::Cover

Review
Make your tests easy to run
Run them often
Test your modules
Test your scripts
Improve your code coverage with Devel::Cover
Use version control, and check in often

Review
Make your tests easy to run
Run them often
Test your modules
Test your scripts
Improve your code coverage with Devel::Cover
Use version control, and check in often
Reuse your test code

Review

Review
Make a test library

Review
Make a test library
Use fixtures

Review
Make a test library
Use fixtures
Mock when necessary

Review
Make a test library
Use fixtures
Mock when necessary
Test quietly if you don’t have support

Review
Make a test library
Use fixtures
Mock when necessary
Test quietly if you don’t have support
Start with the most-changed part of the code

Questions?

Thanks!
• Michael Schwern
• Kirrily Robert
• OSDC
• realestate.com.au
• you

Josh Heumann
josh@joshheumann.com