Making a Bundle Compatible with Symfony 4
If you want to make a bundle compatible with Symfony 4, here are the basic steps:
Update the composer.json file: any symfony/* libraries need to have |4.0 added to it. For example, you would change "symfony/form": "~3.0" to "symfony/form": "~3.0|^4.0". See a pull request in FOSUserBundle for a full example.
Update the bundle's .travis.yml file so that it is tested against Symfony 4. Want an example? See the same pull request from FOSUserBundle.
That's it! Submit a pull request with these changes and see what happens. If there are failures, you'll need to check the UPGRADE document for 4.0. One common issue is that services automatically become private in Symfony 4. So, you may need to set public="true" on the bundle's services to keep them public. Again, an example speaks 100 words: github.com/knpuniversity/oauth2-client-bundle/pull/68
When you've created the pull request, add a comment in the spreadsheet!
http://symfony.com/blog/helping-prepare-for-symfony-4-bundle-support?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+symfony%2Fblog+%28Symfony+Blog%29