Drupal 10 readiness will be hugely automated, 95% of deprecated Drupal APIs already covered

With the Drupal 8 end of life in a little over two months and Drupal 10's release next year, this is the time of transitions again at Drupal. However, while Drupal 7 to 8 (or 9) was a big move, the transitions from 8 to 9 and 9 to 10 are much smaller and mostly automated.

Drupal 10 is planned to be released in June, August or December 2022 and the tools are getting ready to support that. The two key tools will be the same as the previous upgrade: Upgrade Status and Drupal Rector.

Matt Glaman has been doing amazing work recently in the underlying components of both tools. Thanks to his work on updating phpstan-drupal for Drupal 10 support, Upgrade Status checks deprecated API uses on Drupal 9 too. Since my last update on that, I added reporting of deprecated modules and new system requirements as well.

Ryan Aslett at the Drupal Association built the project analysis job on top of Upgrade Status and that is run on Drupal 9 projects now as well. So we have an idea of the extent of work that will need to be done for Drupal 10 compatibility. I've updated the dev.acquia.com deprecation dashboard to show Drupal 10 results. While projects should not be expected to be Drupal 10 ready at this time, the dashboard helps us prioritise work on certain parts of the tooling to help the ecosystem upgrade.

To support that, Palantir.net has been sponsoring Matt Glaman to also bring Drupal Rector up to date for Drupal 10 readiness. The results are already outstanding! Today, of the 22204 Drupal deprecated API uses identified in Drupal 9 compatible projects. These are green and purple on the chart below. Drupal Rector has automations to fix 95% of them (green). There are a further 5391 non-Drupal deprecated API uses (yellow) including Symfony and PHPUnit deprecated APIs. Those themselves have third party rectors, so the coverage will further improve by including those. That is in the works.

The drupal.org Project Update Bot resolves rectorable deprecated API uses (green) and info/composer issues (blue) when posting patches, so this means that it will be able to resolve most deprecated APIs in its suggested fixes already and we expect it will improve more with third party rectors added.

Drupal 10 itself is a moving target, the branch will be open around October/November so the above does not mean that the tools are complete, but we are significantly further ahead this time compared to the Drupal 8 to 9 transition, making the upgrade to Drupal 10 smoother for everyone.

With the Drupal 8 release, we decided upgrades must be easier going forward and thanks to the fantastic work of contributors and sponsors, we are doing it again.