Added an article to explain how to upgrade third-party bundles to Sym…

…fony 3

cookbook/map.rst.inc

@@ -227,6 +227,7 @@
   * :doc:`/cookbook/upgrade/patch_version`
   * :doc:`/cookbook/upgrade/minor_version`
   * :doc:`/cookbook/upgrade/major_version`
+  * :doc:`/cookbook/upgrade/bundles`
 
 * :doc:`/cookbook/validation/index`
 

cookbook/upgrade/bundles.rst

@@ -0,0 +1,36 @@
+.. index::
+    single: Upgrading; Bundle; Major Version
+
+Upgrading a Third-Party Bundle for a Major Symfony Version
+==========================================================
+
+Symfony 3 was released on November 2015. Although this version doesn't contain
+any new feature, it removes all the backwards compatibility layers included in
+the previous 2.8 version. If your bundle uses any deprecated feature and it's
+published as a third-party bundle, applications upgrading to Symfony 3 will no
+longer be able to use it.
+
+Allow to Install Symfony 3 Components
+-------------------------------------
+
+.. TODO
+
+* Change symfony/... ~2.N by ~2.N|~3.M
+
+Look for Deprecations and Fix Them
+----------------------------------
+
+.. TODO
+
+* 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)
+
+Test your Bundle in Symfony 3
+-----------------------------
+
+.. TODO
+
+* 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.

cookbook/upgrade/index.rst

@@ -16,3 +16,4 @@ There are three types of upgrades, all needing a little different preparation:
     /cookbook/upgrade/patch_version
     /cookbook/upgrade/minor_version
     /cookbook/upgrade/major_version
+    /cookbook/upgrade/bundles