How to keep your Drupal 8 contributed modules ready for Drupal 9

In this blog post, we'll have a look at how contributed Drupal modules can remove the core deprecation warnings and be compatible with both Drupal 8 and Drupal 9.

by jibran.ijaz /

Ever since Drupal Europe, we know Drupal 9 will be released in 2020. As per @catch’s comment in 2608496-54

We already have the continuous upgrade path policy which should mean that any up-to-date Drupal 8 module should work with Drupal 9.0.0, either with zero or minimal changes.

Drupal core has a proper deprecation process so it can be continuously improved. Drupal core also has a continuous process of removing deprecated code usages in core should not trigger deprecated code except in tests and during updates, because of proper deprecation testing.

The big problem for contributed modules aka contrib is the removal of deprecated code usage. To allow contrib to keep up with core's removal of deprecation warnings contrib needs proper deprecation testing which is being discussed in support deprecation testing for contributed modules on Drupal.org.

However, Drupal CI build process can be controlled by a drupalci.yml file found in the project. The documentation about it can be found at customizing DrupalCI Testing for Projects.

It is very easy for contributed modules to remove their usage of deprecated code. All we need is to add the following drupalci.yml file to your contributed modules and fix the fails.

# This is the DrupalCI testbot build file for Dynamic Entity Reference.# Learn to make one for your own drupal.org project:# https://www.drupal.org/drupalorg/docs/drupal-ci/customizing-drupalci-testingbuild:  assessment:    validate_codebase:      phplint:      phpcs:# phpcs will use core's specified version of Coder.        sniff-all-files:true        halt-on-fail:true    testing:# run_tests task is executed several times in order of performance speeds.# halt-on-fail can be set on the run_tests tasks in order to fail fast.# suppress-deprecations is false in order to be alerted to usages of# deprecated code.
      run_tests.phpunit:
        types:'PHPUnit-Unit'        testgroups:'--all'        suppress-deprecations:false        halt-on-fail:false
      run_tests.kernel:
        types:'PHPUnit-Kernel'        testgroups:'--all'        suppress-deprecations:false        halt-on-fail:false
      run_tests.functional:
        types:'PHPUnit-Functional'        testgroups:'--all'        suppress-deprecations:false        halt-on-fail:false
      run_tests.javascript:
        concurrency:15        types:'PHPUnit-FunctionalJavascript'        testgroups:'--all'        suppress-deprecations:false        halt-on-fail:false

This drupalci.yml will check all the Drupal core coding standards. This can be disabled by the following change:

      phpcs:# phpcs will use core's specified version of Coder.        sniff-all-files:false        halt-on-fail:false

This file also only runs PHPUnit tests, to run legacy Simpletest you have to the following block:

      run_tests.simpletest:types:'Simpletest'
         testgroups:'--all'
         suppress-deprecations: false
         halt-on-fail: false

But if you still have those, you probably want to start there, because they won't be supported in Drupal 9.

Last but not the least if you think the is module is not ready yet to fix all the deprecation warning you can set suppress-deprecations: true.

As a contrib module maintainer or a contrib module consumer I encourage you to add this file to all the contrib modules you maintain or use, or at least create an issue in the module's issue queue so that at the time of Drupal 9 release all of your favourite modules will be ready. JSONAPI module added this file in https://www.drupal.org/node/2982964 which inspired me to add this to DER in https://www.drupal.org/node/3001640.