Completed the section "Look for Deprecations and Fix Them"

Author: javiereguiluz

cookbook/upgrade/bundles.rst

@@ -22,7 +22,7 @@ Most third-party bundles define their Symfony dependencies using the ``~2.N`` or
         "require": {
             "symfony/framework-bundle": "~2.3",
             "symfony/finder": "~2.3",
-            "symfony/validator": "~2.3",
+            "symfony/validator": "~2.3"
         }
     }
 
@@ -39,18 +39,61 @@ The above example can be updated to work with Symfony 3 as follows:
         "require": {
             "symfony/framework-bundle": "~2.3|~3.0",
             "symfony/finder": "~2.3|~3.0",
-            "symfony/validator": "~2.3|~3.0",
+            "symfony/validator": "~2.3|~3.0"
         }
     }
 
 Look for Deprecations and Fix Them
 ----------------------------------
 
-.. TODO
+Besides allowing to install Symfony 3 component, your bundle must stop using
+any feature deprecated in 2.8 version, because they'll throw exceptions in 3.0
+version. The easiest way to detect deprecations is to install the `PHPUnit Bridge`_
+component and then run the test suite.
+
+First, install the component as a ``dev`` dependency of your bundle:
+
+.. code-block:: bash
+
+    $ composer require --dev "symfony/phpunit-bridge"
+
+Then, run your test suite and look for the deprecation list displayed after the
+PHPUnit test report:
+
+.. code-block:: bash
+
+    $ phpunit
+
+    // ... PHPUnit output ...
 
-* Install: composer require --dev "symfony/phpunit-bridge" and run your test suite
-* Use for basic fixes: https://github.com/umpirsky/Symfony-Upgrade-Fixer
-* Read the "UPGRADE from 2.x to Sf3" guide (https://github.com/symfony/symfony/blob/2.8/UPGRADE-3.0.md)
+    Remaining deprecation notices (3)
+
+    The "pattern" option in file ... is deprecated since version 2.2 and will be
+    removed in 3.0. Use the "path" option in the route definition instead ...
+
+    Twig Function "form_enctype" is deprecated. Use "form_start" instead in ...
+
+    The Symfony\Component\Security\Core\SecurityContext class is deprecated since
+    version 2.6 and will be removed in 3.0. Use ...
+
+Fix the reported deprecations, run the test suite again and repeat the process
+until no deprecation usage is reported.
+
+Useful Resources
+~~~~~~~~~~~~~~~~
+
+There are several resources that can help you detect, understand and fix the use
+of deprecated features:
+
+* `Official Symfony Guide to Upgrade from 2.x to 3.0`_, the full list of changes
+  required to upgrade to Symfony 3.0 and grouped by component.
+* `SensioLabs DeprecationDetector`_, it runs a static code analysis against your
+  project's source code to find usages of deprecated methods, classes and
+  interfaces. It works for any PHP application, but it includes special detectors
+  for Symfony application, where it can also detect usages of deprecated services.
+* `Symfony Upgrade Fixer`_, it analyzes Symfony projects to find deprecations. In
+  addition it solves automatically some of them thanks to the growing list of
+  supported "fixers".
 
 Test your Bundle in Symfony 3
 -----------------------------
@@ -60,3 +103,8 @@ Test your Bundle in Symfony 3
 * Upgrade a test app to Sf3 or create an empty app (symfony new my_app 3.0)
 * Use the "ln -s my_bundle vendor/.../my_bundle" trick to use the new code in the 3.0 app
 * Configure Travis CI to test your bundle in both 2 and 3 versions.
+
+.. _`PHPUnit Bridge`: https://github.com/symfony/phpunit-bridge
+.. _`Official Symfony Guide to Upgrade from 2.x to 3.0`: https://github.com/symfony/symfony/blob/2.8/UPGRADE-3.0.md
+.. _`SensioLabs DeprecationDetector`: https://github.com/sensiolabs-de/deprecation-detector
+.. _`Symfony Upgrade Fixer`: https://github.com/umpirsky/Symfony-Upgrade-Fixer