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NAME

       Catalyst::Manual::Tutorial::08_Testing - Catalyst Tutorial - Chapter 8: Testing

OVERVIEW

       This is Chapter 8 of 10 for the Catalyst tutorial.

       Tutorial Overview

       1.  Introduction

       2.  Catalyst Basics

       3.  More Catalyst Basics

       4.  Basic CRUD

       5.  Authentication

       6.  Authorization

       7.  Debugging

       8.  08_Testing

       9.  Advanced CRUD

       10. Appendices

DESCRIPTION

       You may have noticed that the Catalyst Helper scripts automatically create basic ".t" test
       scripts under the "t" directory.  This chapter of the tutorial briefly looks at how these
       tests can be used not only to ensure that your application is working correctly at the
       present time, but also provide automated regression testing as you upgrade various pieces
       of your application over time.

       Source code for the tutorial in included in the /home/catalyst/Final directory of the
       Tutorial Virtual machine (one subdirectory per chapter).  There are also instructions for
       downloading the code in Catalyst::Manual::Tutorial::01_Intro.

       For an excellent introduction to learning the many benefits of testing your Perl
       applications and modules, you might want to read 'Perl Testing: A Developer's Notebook' by
       Ian Langworth and chromatic.

RUNNING THE "CANNED" CATALYST TESTS

       There are a variety of ways to run Catalyst and Perl tests (for example, "perl
       Makefile.PL" and "make test"), but one of the easiest is with the "prove" command.  For
       example, to run all of the tests in the "t" directory, enter:

           $ prove -wl t

       There will be a lot of output because we have the "-Debug" flag enabled in lib/MyApp.pm
       (see the "CATALYST_DEBUG=0" tip below for a quick and easy way to reduce the clutter).
       Look for lines like this for errors:

           #   Failed test 'Request should succeed'
           #   at t/controller_Books.t line 8.
           # Looks like you failed 1 test of 3.

       The redirection used by the Authentication plugins will cause several failures in the
       default tests.  You can fix this by making the following changes:

       1) Change the line in t/01app.t that reads:

           ok( request('/')->is_success, 'Request should succeed' );

       to:

           ok( request('/login')->is_success, 'Request should succeed' );

       2) Change the line in t/controller_Logout.t that reads:

           ok( request('/logout')->is_success, 'Request should succeed' );

       to:

           ok( request('/logout')->is_redirect, 'Request should succeed' );

       3) Change the line in t/controller_Books.t that reads:

           ok( request('/books')->is_success, 'Request should succeed' );

       to:

           ok( request('/books')->is_redirect, 'Request should succeed' );

       4) Add the following statement to the top of t/view_HTML.t:

           use MyApp;

       As you can see in the "prove" command line above, the "-l" option (or "--lib" if you
       prefer) is used to set the location of the Catalyst "lib" directory.  With this command,
       you will get all of the usual development server debug output, something most people
       prefer to disable while running tests cases.  Although you can edit the lib/MyApp.pm to
       comment out the "-Debug" plugin, it's generally easier to simply set the
       "CATALYST_DEBUG=0" environment variable.  For example:

           $ CATALYST_DEBUG=0 prove -wl t

       During the t/02pod.t and t/03podcoverage.t tests, you might notice the "all skipped: set
       TEST_POD to enable this test" warning message.  To execute the Pod-related tests, add
       "TEST_POD=1" to the "prove" command:

           $ CATALYST_DEBUG=0 TEST_POD=1 prove -wl t

       If you omitted the Pod comments from any of the methods that were inserted, you might have
       to go back and fix them to get these tests to pass. :-)

       Another useful option is the "verbose" ("-v") option to "prove".  It prints the name of
       each test case as it is being run:

           $ CATALYST_DEBUG=0 prove -vwl t

RUNNING A SINGLE TEST

       You can also run a single script by appending its name to the "prove" command. For
       example:

           $ CATALYST_DEBUG=0 prove -wl t/01app.t

       Also note that you can also run tests directly from Perl without "prove".  For example:

           $ CATALYST_DEBUG=0 perl -w -Ilib t/01app.t

ADDING YOUR OWN TEST SCRIPT

       Although the Catalyst helper scripts provide a basic level of checks "for free," testing
       can become significantly more helpful when you write your own tests to exercise the
       various parts of your application.  The Test::WWW::Mechanize::Catalyst module is very
       popular for writing these sorts of test cases.  This module extends Test::WWW::Mechanize
       (and therefore WWW::Mechanize) to allow you to automate the action of a user "clicking
       around" inside your application.  It gives you all the benefits of testing on a live
       system without the messiness of having to use an actual web server, and a real person to
       do the clicking.

       To create a sample test case, open the t/live_app01.t file in your editor and enter the
       following:

           #!/usr/bin/env perl

           use strict;
           use warnings;
           use Test::More;

           # Need to specify the name of your app as arg on next line
           # Can also do:
           #   use Test::WWW::Mechanize::Catalyst "MyApp";

           BEGIN { use_ok("Test::WWW::Mechanize::Catalyst" => "MyApp") }

           # Create two 'user agents' to simulate two different users ('test01' & 'test02')
           my $ua1 = Test::WWW::Mechanize::Catalyst->new;
           my $ua2 = Test::WWW::Mechanize::Catalyst->new;

           # Use a simplified for loop to do tests that are common to both users
           # Use get_ok() to make sure we can hit the base URL
           # Second arg = optional description of test (will be displayed for failed tests)
           # Note that in test scripts you send everything to 'http://localhost'
           $_->get_ok("http://localhost/", "Check redirect of base URL") for $ua1, $ua2;
           # Use title_is() to check the contents of the <title>...</title> tags
           $_->title_is("Login", "Check for login title") for $ua1, $ua2;
           # Use content_contains() to match on text in the html body
           $_->content_contains("You need to log in to use this application",
               "Check we are NOT logged in") for $ua1, $ua2;

           # Log in as each user
           # Specify username and password on the URL
           $ua1->get_ok("http://localhost/login?username=test01&password=mypass", "Login 'test01'");
           # Could make user2 like user1 above, but use the form to show another way
           $ua2->submit_form(
               fields => {
                   username => 'test02',
                   password => 'mypass',
               });

           # Go back to the login page and it should show that we are already logged in
           $_->get_ok("http://localhost/login", "Return to '/login'") for $ua1, $ua2;
           $_->title_is("Login", "Check for login page") for $ua1, $ua2;
           $_->content_contains("Please Note: You are already logged in as ",
               "Check we ARE logged in" ) for $ua1, $ua2;

           # 'Click' the 'Logout' link (see also 'text_regex' and 'url_regex' options)
           $_->follow_link_ok({n => 4}, "Logout via first link on page") for $ua1, $ua2;
           $_->title_is("Login", "Check for login title") for $ua1, $ua2;
           $_->content_contains("You need to log in to use this application",
               "Check we are NOT logged in") for $ua1, $ua2;

           # Log back in
           $ua1->get_ok("http://localhost/login?username=test01&password=mypass",
               "Login 'test01'");
           $ua2->get_ok("http://localhost/login?username=test02&password=mypass",
               "Login 'test02'");
           # Should be at the Book List page... do some checks to confirm
           $_->title_is("Book List", "Check for book list title") for $ua1, $ua2;

           $ua1->get_ok("http://localhost/books/list", "'test01' book list");
           $ua1->get_ok("http://localhost/login", "Login Page");
           $ua1->get_ok("http://localhost/books/list", "'test01' book list");

           $_->content_contains("Book List", "Check for book list title") for $ua1, $ua2;
           # Make sure the appropriate logout buttons are displayed
           $_->content_contains("/logout\">User Logout</a>",
               "Both users should have a 'User Logout'") for $ua1, $ua2;
           $ua1->content_contains("/books/form_create\">Admin Create</a>",
               "'test01' should have a create link");
           $ua2->content_lacks("/books/form_create\">Admin Create</a>",
               "'test02' should NOT have a create link");

           $ua1->get_ok("http://localhost/books/list", "View book list as 'test01'");

           # User 'test01' should be able to create a book with the "formless create" URL
           $ua1->get_ok("http://localhost/books/url_create/TestTitle/2/4",
               "'test01' formless create");
           $ua1->title_is("Book Created", "Book created title");
           $ua1->content_contains("Added book 'TestTitle'", "Check title added OK");
           $ua1->content_contains("by 'Stevens'", "Check author added OK");
           $ua1->content_contains("with a rating of 2.", "Check rating added");
           # Try a regular expression to combine the previous 3 checks & account for whitespace
           $ua1->content_like(qr/Added book 'TestTitle'\s+by 'Stevens'\s+with a rating of 2./,
               "Regex check");

           # Make sure the new book shows in the list
           $ua1->get_ok("http://localhost/books/list", "'test01' book list");
           $ua1->title_is("Book List", "Check logged in and at book list");
           $ua1->content_contains("Book List", "Book List page test");
           $ua1->content_contains("TestTitle", "Look for 'TestTitle'");

           # Make sure the new book can be deleted
           # Get all the Delete links on the list page
           my @delLinks = $ua1->find_all_links(text => 'Delete');
           # Use the final link to delete the last book
           $ua1->get_ok($delLinks[$#delLinks]->url, 'Delete last book');
           # Check that delete worked
           $ua1->content_contains("Book List", "Book List page test");
           $ua1->content_like(qr/Deleted book \d+/, "Deleted book #");

           # User 'test02' should not be able to add a book
           $ua2->get_ok("http://localhost/books/url_create/TestTitle2/2/5", "'test02' add");
           $ua2->content_contains("Unauthorized!", "Check 'test02' cannot add");

           done_testing;

       The live_app.t test cases uses copious comments to explain each step of the process.  In
       addition to the techniques shown here, there are a variety of other methods available in
       Test::WWW::Mechanize::Catalyst (for example, regex-based matching). Consult
       Test::WWW::Mechanize::Catalyst, Test::WWW::Mechanize, WWW::Mechanize, and Test::More for
       more detail.

       TIP: For unit tests vs. the "full application tests" approach used by
       Test::WWW::Mechanize::Catalyst, see Catalyst::Test.

       Note: The test script does not test the "form_create" and "form_create_do" actions.  That
       is left as an exercise for the reader (you should be able to complete that logic using the
       existing code as a template).

       To run the new test script, use a command such as:

           $ CATALYST_DEBUG=0 prove -vwl t/live_app01.t

       or

           $ DBIC_TRACE=0 CATALYST_DEBUG=0 prove -vwl t/live_app01.t

       Experiment with the "DBIC_TRACE", "CATALYST_DEBUG" and "-v" settings.  If you find that
       there are errors, use the techniques discussed in the "Catalyst Debugging" section
       (Chapter 7) to isolate and fix any problems.

       If you want to run the test case under the Perl interactive debugger, try a command such
       as:

           $ DBIC_TRACE=0 CATALYST_DEBUG=0 perl -d -Ilib t/live_app01.t

       Note that although this tutorial uses a single custom test case for simplicity, you may
       wish to break your tests into different files for better organization.

       TIP: If you have a test case that fails, you will receive an error similar to the
       following:

           #   Failed test 'Check we are NOT logged in'
           #   in t/live_app01.t at line 31.
           #     searched: "\x{0a}<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Tran"...
           #   can't find: "You need to log in to use this application."

       Unfortunately, this only shows us the first 50 characters of the HTML returned by the
       request -- not enough to determine where the problem lies.  A simple technique that can be
       used in such situations is to temporarily insert a line similar to the following right
       after the failed test:

           diag $ua1->content;

       This will cause the full HTML returned by the request to be displayed.

       Another approach to see the full HTML content at the failure point in a series of tests
       would be to insert a ""$DB::single=1;" right above the location of the failure and run the
       test under the Perl debugger (with "-d") as shown above.  Then you can use the debugger to
       explore the state of the application right before or after the failure.

SUPPORTING BOTH PRODUCTION AND TEST DATABASES

       You may wish to leverage the techniques discussed in this tutorial to maintain both a
       "production database" for your live application and a "testing database" for your test
       cases.  One advantage to Test::WWW::Mechanize::Catalyst is that it runs your full
       application; however, this can complicate things when you want to support multiple
       databases.

   DATABASE CONFIG SWITCHING IN YOUR MODEL CLASS
       One solution is to allow the database specification to be overridden with an environment
       variable.  For example, open lib/MyApp/Model/DB.pm in your editor and change the
       "__PACKAGE__->config(..." declaration to resemble:

           my $dsn = $ENV{MYAPP_DSN} ||= 'dbi:SQLite:myapp.db';
           __PACKAGE__->config(
               schema_class => 'MyApp::Schema',

               connect_info => {
                   dsn => $dsn,
                   user => '',
                   password => '',
                   on_connect_do => q{PRAGMA foreign_keys = ON},
               }
           );

       Then, when you run your test case, you can use commands such as:

           $ cp myapp.db myappTEST.db
           $ CATALYST_DEBUG=0 MYAPP_DSN="dbi:SQLite:myappTEST.db" prove -vwl t/live_app01.t

       This will modify the DSN only while the test case is running.  If you launch your normal
       application without the "MYAPP_DSN" environment variable defined, it will default to the
       same "dbi:SQLite:myapp.db" as before.

   DATABASE CONFIG SWITCHING USING MULTIPLE CONFIG FILES
       Catalyst::Plugin::ConfigLoader has functionality to load multiple config files based on
       environment variables, allowing you to override your default (production) database
       connection settings during development (or vice versa).

       Setting $ENV{ MYAPP_CONFIG_LOCAL_SUFFIX } to 'testing' in your test script results in
       loading of an additional config file named myapp_testing.conf after myapp.conf which will
       override any parameters in myapp.conf.

       You should set the environment variable in the BEGIN block of your test script to make
       sure it's set before your Catalyst application is started.

       The following is an example for a config and test script for a DBIx::Class model named
       MyDB and a controller named Foo:

       myapp_testing.conf:

           <Model::MyDB>
               <connect_info>
                   dsn dbi:SQLite:myapp.db
               </connect_info>
           </Model::MyDB>

       t/controller_Foo.t:

           use strict;
           use warnings;
           use Test::More;

           BEGIN {
               $ENV{ MYAPP_CONFIG_LOCAL_SUFFIX } = 'testing';
           }

           eval "use Test::WWW::Mechanize::Catalyst 'MyApp'";
           plan $@
               ? ( skip_all => 'Test::WWW::Mechanize::Catalyst required' )
               : ( tests => 2 );

           ok( my $mech = Test::WWW::Mechanize::Catalyst->new, 'Created mech object' );

           $mech->get_ok( 'http://localhost/foo' );

       You can jump to the next chapter of the tutorial here: Advanced CRUD

AUTHOR

       Kennedy Clark, "hkclark@gmail.com"

       Feel free to contact the author for any errors or suggestions, but the best way to report
       issues is via the CPAN RT Bug system at
       <https://rt.cpan.org/Public/Dist/Display.html?Name=Catalyst-Manual>.

       Copyright 2006-2011, Kennedy Clark, under the Creative Commons Attribution Share-Alike
       License Version 3.0 (<https://creativecommons.org/licenses/by-sa/3.0/us/>).