Upgrading to Symfony 5.0

We've done it! We fixed all the deprecations in our app... except for the doctrine/persistence stuff, which we don't need to worry about because we're not upgrading that library. That means... we are ready for Symfony5!

Changing composer.json for Symfony 5.0

How... do we actually upgrade? We already know: it's the exact same process we used to upgrade from 4.3 to 4.4.

Open up composer.json. Our goal is to update all of these symfony/ libraries to 5.0:

Well, not quite all of them - a few are not part of the main Symfony library, like monolog-bundle. But basically, everything that has 4.4.* now needs to be 5.0.*.

We also need to update one more thing: the extra.symfony.require value:

This is primarily a performance optimization that helps Composer filter out extra Symfony versions when it's trying to resolve packages. This also needs to change to 5.0.*.

Let's... do it all at once: Find 4.4.*, replace it with 5.0.* and hit "Replace all":

And then... make sure that this didn't accidentally replace any non-Symfony packages that may have had the same version.... looks good.

Updating Symfony Packages in Composer

We're ready! At your terminal... I'll hit Ctrl+C to stop the log tail.... and run the same command we used when upgrading from Symfony 4.3 to 4.4:

composer update "symfony/*"

That's it! It's that easy! We're done! Kidding - it's never that easy: you will almost definitely get some dependency errors. Probably... several. Ah, here's our first.

Composer: Many Packages Need to Update

These errors are always a little hard to read. This says that the current version of doctrine/orm in our project is not compatible with Symfony 5... which means that it also needs to be updated. Specifically we need a newer version that's compatible with symfony/console version 5.

And... it's possible that there is not yet a release of doctrine/orm that supports Symfony 5 - we hit that problem earlier with StofDoctrineExtensionsBundle. But... let's blindly try it! Add doctrine/orm to our update list and try again:

composer update "symfony/*" doctrine/orm

And... another error. Actually, the same error but this time for knplabs/knp-markdown-bundle. We don't know if this bundle has a Symfony5-compatible release either... and even if it does... it might require a major version upgrade. But the easiest thing to do is add it to our list and hope for the best. Try it:

composer update "symfony/*" doctrine/orm knplabs/knp-markdown-bundle

So... this is going to happen several more times - this is the same error for knplabs/knp-snappy-bundle. Little-by-little, we're discovering all the packages that we need to upgrade to be compatible with Symfony 5. Instead of doing this one-by-one, you can also choose the easy route: just run composer update with no arguments and allow Composer to update everything.

I prefer to upgrade more cautiously than that... but it's not a bad option. After all, our Composer version constraints don't allow any major version upgrades: so running composer update still won't allow any new major package versions unless you tweaked your composer.json file.

Let's keep going with my cowardly, I mean, cautious way: copy the package name and add it to the update command:

composer update "symfony/*" \
                doctrine/orm \
                knplabs/knp-markdown-bundle \
                knplabs/knp-snappy-bundle

Let's keep trying and... I'll fast-forward through a few more of these: this is for liip/imagine-bundle - add that to the update command - then oneup/flysystem-bundle... and now sensio/framework-extra-bundle: add that to our very-long update command:

composer update "symfony/*" \
                doctrine/orm \
                knplabs/knp-markdown-bundle \
                knplabs/knp-snappy-bundle \
                liip/imagine-bundle \
                oneup/flysystem-bundle \
                sensio/framework-extra-bundle

Updating --with-dependencies

Hmm, but this next error looks a bit different: it's something about doctrine/orm and doctrine/instantiator. If you look closely, this says that in order to get Symfony 5 support, we need doctrine/orm version 2.7, but version 2.7 requires doctrine/instantiator 1.3... and our project is currently locked at version 1.2.

Our app doesn't require doctrine/instantiator directly: it's a dependency of doctrine/orm. We saw this earlier when we were updating doctrine-migrations-bundle and we also needed to allow its dependency - doctrine/migrations to update.

We allow that by adding --with-dependencies to the update command:

composer update "symfony/*" \
                doctrine/orm \
                knplabs/knp-markdown-bundle \
                knplabs/knp-snappy-bundle \
                liip/imagine-bundle \
                oneup/flysystem-bundle \
                sensio/framework-extra-bundle \
                --with-dependencies

Updating our PHP Version

And... this gets us to our next error. Oh, interesting! Apparently nexylan/slack-bundle version 2.2.1 requires PHP 7.3! We saw a similar error earlier, which caused us to decide that our production app would now need to at least run PHP 7.2. We enforced that by adding a config.platform.php setting in composer.json to 7.2.5. This says:

Yo Composer! Pretend I'm using PHP 7.2.5 and don't let me use any packages that require a higher version of PHP.

So... hmm. Apparently the version of nexylan/slack-bundle that supports Symfony 5 requires PHP 7.3. Basically... unless we want to stop using that bundle, it means that we need to start using PHP 7.3 as well.

Fortunately, I'm already using PHP 7.3 locally: so I just need to change my config.platform.php setting to 7.3 and also makes sure that we have 7.3 on production.

Inside composer.json, search for platform: there it is. Use 7.3.0. And, even though it doesn't affect anything in a project, also change the version under the require key:

Ok, now try to update:

composer update "symfony/*" \
                doctrine/orm \
                knplabs/knp-markdown-bundle \
                knplabs/knp-snappy-bundle \
                liip/imagine-bundle \
                oneup/flysystem-bundle \
                sensio/framework-extra-bundle \
                --with-dependencies

Bah! I should've seen that coming: it's still complaining about nexylan/slack-bundle: it's reminding us that we need to also allow that bundle to update. Add it to our list:

composer update "symfony/*" \
                doctrine/orm \
                knplabs/knp-markdown-bundle \
                knplabs/knp-snappy-bundle \
                liip/imagine-bundle \
                oneup/flysystem-bundle \
                sensio/framework-extra-bundle \
                nexylan/slack-bundle \
                --with-dependencies

And try it. Surprise! Another package needs to be update. I swear we're almost done. Add that to our gigantic update command:

sed -i 's/"4.4.*"/"5.0.*"/g' ./composer.json
sed -i 's/public function getExtendedType()/public static function getExtendedTypes(): iterable/g' ./src/Form/TypeExtension/TextareaSizeExtension.php
sed -i 's/TextareaType::class/\[TextareaType::class\]/g' ./src/Form/TypeExtension/TextareaSizeExtension.php
sed -i 's/extends Controller/extends AbstractController/g' ./src/Controller/CommentAdminController.php
sed -i 's/use Symfony\\Bundle\\FrameworkBundle\\Controller\\Controller/use Symfony\\Bundle\\FrameworkBundle\\Controller\\AbstractController/g' ./src/Controller/CommentAdminController.php
sed -i 's/use Doctrine\\Common\\Persistence\\ObjectManager/use Doctrine\\Persistence\\ObjectManager/g' ./src/DataFixtures/ArticleFixtures.php
sed -i 's/use Doctrine\\Common\\Persistence\\ObjectManager/use Doctrine\\Persistence\\ObjectManager/g' ./src/DataFixtures/BaseFixture.php
sed -i 's/use Doctrine\\Common\\Persistence\\ObjectManager/use Doctrine\\Persistence\\ObjectManager/g' ./src/DataFixtures/CommentFixture.php
sed -i 's/use Doctrine\\Common\\Persistence\\ObjectManager/use Doctrine\\Persistence\\ObjectManager/g' ./src/DataFixtures/TagFixture.php
sed -i 's/use Doctrine\\Common\\Persistence\\ObjectManager/use Doctrine\\Persistence\\ObjectManager/g' ./src/DataFixtures/UserFixture.php
echo "delete duplicated file" && rm config/routes/dev/twig.yaml

composer update "symfony/*" \
                doctrine/orm \
                knplabs/knp-markdown-bundle \
                knplabs/knp-snappy-bundle \
                liip/imagine-bundle \
                oneup/flysystem-bundle \
                sensio/framework-extra-bundle \
                nexylan/slack-bundle \
                knplabs/knp-time-bundle \
                easycorp/easy-log-handler \
                knplabs/knp-paginator-bundle \
                stof/doctrine-extensions-bundle \
                doctrine/doctrine-bundle \
                doctrine/doctrine-fixtures-bundle \
                doctrine/doctrine-migrations-bundle \
                twig/cssinliner-extra \
                --with-dependencies

Other than Symfony: (Mostly) Only Safe Minor Upgrades

And... whaaaat? It's working! It's upgrading a ton of packages, including the Symfony stuff to 5.0.2. And, because we didn't change any other version constraints inside composer.json, we know that all of these upgrades are just minor version upgrades at best. For example, nexylan/slack-bundle went from 2.1 to 2.2. Even if there were a new version 3 of this bundle, we know that it wouldn't upgrade to it because its version constraint is ^2.1, which allows 2.1 or higher, but not 3:

Well, that's not completely true: check out nexylan/slack: it went from version 2.3 to 3: that is a major upgrade. That's because this is one of those transitive dependencies: this package isn't in our composer.json, it only lives in our project because nexylan/slack-bundle requires it. So unless we're using its code directly - which is possible, but less likely - the major upgrade won't affect us. If you're worried, check its CHANGELOG.

Ok, so we are now on Symfony 5. Woo! The little icon on the bottom right of the web debug toolbar shows 5.0.2.

Next, let's celebrate by trying out some new features! We'll start by talking about Symfony's new "secrets management".