Composer-enabled Drupal template

This is Pantheon's recommended starting point for forking new Drupal upstreams that work with the Platform's Integrated Composer build process. It is also the Platform's standard Drupal 9 upstream.

Unlike with earlier Pantheon upstreams, files such as Drupal Core that you are unlikely to adjust while building sites are not in the main branch of the repository. Instead, they are referenced as dependencies that are installed by Composer.

For more information and detailed installation guides, please visit the Integrated Composer Pantheon documentation: https://pantheon.io/docs/integrated-composer

Drupal Core Version Management

This upstream currently requires Drupal 11.3.5 or higher. The version constraints use the caret (^) operator, which allows:

• ✅ Patch updates (e.g., 11.3.6, 11.3.7)
• ✅ Minor updates (e.g., 11.4.0, 11.5.0)
• ❌ Major updates (e.g., 12.0.0)

This ensures automatic security updates while maintaining API compatibility.

When to Update Drupal Core Versions

Update the minimum Drupal core version when:

• Security releases require a minimum version
• Bug fixes in newer versions are needed for stability
• New features in Drupal core are required by the upstream
• Maintaining compatibility with Pantheon platform updates

How to Update

1. Update all core packages together in composer.json:

   • drupal/core-composer-scaffold
   • drupal/core-project-message
   • drupal/core-recommended
   • drupal/core-dev

2. Test the changes (see TESTING.md for detailed procedures)

3. Update CHANGELOG.md with the change

4. Create a pull request with clear rationale for the version update

See TESTING.md for comprehensive validation procedures.

Contributing

Contributions are welcome in the form of GitHub pull requests. However, the pantheon-upstreams/drupal-composer-managed repository is a mirror that does not directly accept pull requests.

Instead, to propose a change, please fork pantheon-systems/drupal-composer-managed and submit a PR to that repository.

Merging updates from your upstream.

To manually apply changes from the external upstream repository (branch: main):

1. Add the upstream repository as a remote (if not already added):

   git remote add upstream https://github.com/bluecadet/upstream.git

   Replace bluecadet with the correct organization or user name.

2. Fetch the latest changes from upstream:

   git fetch upstream

3. Merge the upstream main branch into your current branch:

   git merge upstream/main

4. Resolve any merge conflicts if they occur, then commit the result.

5. Push your changes to your fork or origin as needed.

For more details, see the GitHub documentation on syncing a fork.