Rodolfo Carvalho - @201YAPC::Brasil 2011

Rodolfo Carvalho

● Eng. Computação UFRJ

● PythOnRio

● Coding Dojo Rio

● Ex-Globo.com, ex-Intelie

● Entusiasta de Racket

● Monge Perl?

Quem sabe em breve :P

metacpan.org

CPAN: Comprehensive Perl Archive Network

Desenvolvimento "tradicional"

Design

Code

Test

TDD: Test-Driven Development

Design

Code

Test

Test

Refactor

No longo prazo...

...

tempo

x

● CPAN contém diversas opções

● TAP: "Test Anything Protocol"

Test::SimpleTest::More + Test::Exception Test::Differences Test::Deep Test::Warn = Test::Most

Em Perl

+ prove

Exemplo

Problema: calcular o n-ésimo número da sequência de Fibonacci. Design: escrever uma função que recebe um argumento numérico (n) e retorna o número da sequência correspondente.

Exemplo: Fibonacci

Teste:use Test::More; is( fibonacci(0), 0 ); done_testing();

Resultado:$ prove fibonacci.pl fibonacci.pl .. Undefined subroutine &main::fibonacci called at fibonacci.pl line 4.fibonacci.pl .. Dubious, test returned 9 (wstat 2304, 0x900)

Exemplo: Fibonacci

Implementação:sub fibonacci {

return 0;}

Resultado:$ prove fibonacci.pl fibonacci.pl .. ok All tests successful.

Exemplo: Fibonacci

...

Exemplo: Fibonacci

Teste:is( fibonacci(0), 0 );is( fibonacci(1), 1 );is( fibonacci(2), 1 );

Implementação:sub fibonacci { my $n = shift; return 0 if $n eq 0; return 1 if $n eq 1; return 1 if $n eq 2;}

Exemplo: Fibonacci

Teste:is( fibonacci(0), 0 );is( fibonacci(1), 1 );is( fibonacci(2), 1 );is( fibonacci(3), 2 );

Resultado:$ prove fibonacci.pl fibonacci.pl .. 1/? # Failed test at fibonacci.pl line 15.# got: ''# expected: '2'# Looks like you failed 1 test of 4.

Exemplo: Fibonacci

Implementação:sub fibonacci {

my $n = shift;return 0 if $n eq 0;return 1 if $n eq 1;return fibonacci($n-2) +

fibonacci($n-1);}

Resultado:$ prove fibonacci.pl fibonacci.pl .. ok All tests successful.

Exemplo: Fibonacci

Teste:my $phi = (1+sqrt 5)/2;my $psi = -1/$phi;foreach ( 0..20 ) { is( fibonacci($_), ($phi**$_ - $psi**$_)/ sqrt 5 );}

Resultado:$ prove fibonacci.pl fibonacci.pl .. ok All tests successful.

oferece muito mais

Perl

OOP's "xUnit"

● Test::Class

● Test::MockObject

● DBD::Mock

● Test::TCP

package Example::Test;use base qw(Test::Class);use Test::More; # setup methods are run before every test method.sub make_fixture : Test(setup) { my $array = [1, 2]; shift->{test_array} = $array;}; # a test method that runs 1 testsub test_push : Test { my $array = shift->{test_array}; push @$array, 3; is_deeply($array, [1, 2, 3], 'push worked');}; # a test method that runs 4 testssub test_pop : Test(4) { my $array = shift->{test_array}; is(pop @$array, 2, 'pop = 2'); is(pop @$array, 1, 'pop = 1'); is_deeply($array, [], 'array empty'); is(pop @$array, undef, 'pop = undef');}; # teardown methods are run after every test method.sub teardown : Test(teardown) { my $array = shift->{test_array}; diag("array = (@$array) after test(s)");};

TDD + Web

● Test::WWW::Mechanize

use Test::More tests => 5;use Test::WWW::Mechanize; my $mech = Test::WWW::Mechanize->new;$mech->get_ok( $page );$mech->base_is( 'http://petdance.com/', 'Proper <BASE HREF>' );$mech->title_is( 'Invoice Status', "Make sure we're on the invoice page" );$mech->text_contains( 'Andy Lester', 'My name somewhere' );$mech->content_like( qr/(cpan|perl)\.org/, 'Link to perl.org or CPAN' );

TDD + Web

● Test::Mojo HTML5 Real-time webapps

use Test::More tests => 10;use Test::Mojo; my $t = Test::Mojo->new('MyApp'); $t->get_ok('/welcome') ->status_is(200) ->content_like(qr/Hello!/, 'welcome message'); $t->post_form_ok('/search', {title => 'Perl', author => 'taro'}) ->status_is(200) ->content_like(qr/Perl.+taro/); $t->delete_ok('/something') ->status_is(200) ->header_is('X-Powered-By' => 'Mojolicious (Perl)') ->header_isnt('X-Bender' => 'Bite my shiny metal ass!'); ->content_is('Hello world!'); $t->websocket_ok('/echo') ->send_message_ok('hello') ->message_is('echo: hello') ->finish_ok;

Test anything...

● Test::Pod::Coverage

● Test::UseAllModules

● Test::NoWarnings

● Test::Perl::Critic

● Test::AskAnExpert

● Test::Inline

● Test::UniqueTestNames

Não basta escrever testes

Fácil:● Dada uma entrada, comparar saída e saída esperada

Difícil:● O que testar

● Como testar

● Erros não previstos

Não basta escrever testesShort list of ways tests could fail without any code change:

● "Temporary" test files and fixtures might be dirty.

● "Temporary" databases and tables might be dirty.

● It is sensitive to time or date.

● It uses network resources and they changed.

● The compiler was changed.

● The installed libraries used were changed.

● The libraries the libraries use were changed.

● The kernel was changed.

● Any servers used (databases, web servers, etc...) were changed.

● It uses parallel processing and a subtle bug only occurs sometimes.

● The disk (or the filesystem where temp files go) is full.

● The disk (or the filesystem where temp files go) is broken.

● Your memory/disk/process/filehandle quotas were reduced.

● The machine has run out of memory.

● The machine has run out of filehandles.

● It uses fixtures with randomly generated data and generated some that tickled a bug.

Michael Schwern

metacpan.org

Quero fazer TDD, e agora?

Coding Dojo

Coding Dojo

● Prática deliberada de TDD

● Programação em par

● Aprendizado coletivo

+ é divertido!

Como funciona?

Precisamos de:● Piloto e co-piloto

● Problema

● Computador

● Projetor

● Cronômetro

● Comida!

5 ~ 7 min

Retrospectiva

Onde

Centro, toda quarta-feira às 18:30Av Treze de Maio, 13 – sala 616

Edifício Municipal

UFF - Niteróiquintas 19:00

TDD+

Perl

Agradecimentos

Breno (Garu) Dojo Rio

Contato about.me/rhcarvalho

dojorio.org