Test automatici2 per applicazioni WebStefano Rodighiero - larsen@perl.it

Scrivere software =

Gestire la complessità

Complessità

You might think of this as mental juggling - the more mental balls the program requires you to keep in the air at once, the

more likely you’ll drop one of the balls, leading to a design or coding error.

-- Steve McConnell

• Loose coupling

• Tecniche standard

• KISS

• Test?

Gestire la complessità

Test?

«Testing by itself does not improve software quality. [...] Trying to improve software by increasing the amount of testing is like trying to lose weight by weighting yourself more often»

-- Steve McConnell

Test!

• Aumenta indirettamente la qualità del software

• Design for testing

• Refactoring

• Wishful thinking

• Confidenza con il proprio codice

Esempio

#!/usr/bin/perl -w

use Test::Simple tests => 2; use Date::ICal;

my $ical = Date::ICal->new; # make an objectok( defined $ical ); # check we got something ok( $ical->isa('Date::ICal') ); # and it's the right class

Gradualmente

• prova.pl → t/01_base.t

• diag()

• Usare gli occhi

• map <F8> :! prove %<C-M>

• YMMV :)

Applicazioni web

Paradigma MVC

Presentazione Model

Controllo

• Situazioni difficili da riprodurre

• Grande complessità

• Chi effettua il test non è il programmatore

Test di videogame

?

• Workflow complessi

• Quello che non è automatico tende a non essere fatto

Test di applicazioni web

WWW::Mechanize

#!/usr/bin/perl

use strict;use warnings;

use WWW::Mechanize;

my $agent = WWW::Mechanize->new();$agent->get( 'http://www.google.com' );print $agent->content();

Test::WWW::Mechanize

#!/usr/bin/perl

use strict;use warnings;

use Test::More qw/ no_plan /;use Test::WWW::Mechanize;

my $agent = Test::WWW::Mechanize->new();$agent->get_ok( 'http://www.google.com' );$agent->title_is( 'Google' );

WWW::Mechanize::Shell

calvin:~ larsen$ perl -MWWW::Mechanize::Shell -e shell>g http://www.google.comRetrieving http://www.google.com(200)http://www.google.com>script mech3.plhttp://www.google.com>quitcalvin:~ larsen$

WWW::Mechanize::Shell

#!perl -wuse strict;use WWW::Mechanize;use WWW::Mechanize::FormFiller;use URI::URL;

my $agent = WWW::Mechanize->new( autocheck => 1 );my $formfiller = WWW::Mechanize::FormFiller->new();$agent->env_proxy();

$agent->get('http://www.google.com');$agent->form(1) if $agent->forms and scalar @{$agent->forms};

mech3.pl

HTTP::Recorder

proxy.pl#!/usr/bin/perl

use strict;use warnings;

use HTTP::Proxy qw/ :log /;use HTTP::Recorder;

my $proxy = HTTP::Proxy->new;my $agent = HTTP::Recorder->new( file => "/tmp/tmpfile" , showwindow => 1 );

$proxy->logmask( STATUS | PROCESS | HEADERS );$proxy->port( 3128 );$proxy->host( '' );$proxy->agent( $agent );$proxy->start();

Demo

Idee

• Usare proxy.pl con un sistema di bugtracking (il ticket contiene il codice per riprodurre l’errore)

• Testare applicazioni non scritte in Perl

• Screenscraping

Conclusioni

• Integrate le pratiche di testing nel vostro workflow lavorativo

• Gradualmente!

• Sono pratiche che pagano da subito

• Come posso progettare il codice per facilitarne il test?

Monday, I could wait till TuesdayIf I make up my mindWednesday would be fine, Thursday’s on my mindFriday’d give me time, Saturday could waitBut Sunday’d be too late-- Sting

larsen@perl.ithttp://larsen.perlmonk.org/blog

Grazie :)

Riferimenti• Web Testing with HTTP::Recorder http://www.perl.com/pub/a/2004/06/04/recorder.html

• Test di applicazioni web http://www.perl.it/blog/archives/000036.html

• A Perl Testing Tutorial (PDF) http://www.wgz.org/chromatic/perl/IntroTestMore.pdf

• Migliorare la navigazione sul web con Perl http://www.perl.it/blog/archives/000076.html

• Documentazione dei vari moduli menzionati http://search.cpan.org/