Composer Module Removal Order

What: Never remove modules from composer.json before all environments have uninstalled them via drush config:import. CI/CD runs composer install — missing packages cause fatal errors.

Rationale: Module uninstall is a config operation: it removes the module from core.extension.yml and lets Drupal cleanly remove its config and tables. If you remove the package from composer.json first, the next composer install fails to find a module that's still listed in active config. The site bootstraps fail with class-not-found errors, deployments break, and rolling back means re-adding the package.

When it applies: Every module removal. The correct sequence: uninstall via UI/drush → export config (removes from core.extension) → deploy that config to all environments → THEN remove from composer.json → deploy.

Example:

# Right — sequenced removal
# Step 1: locally
drush pm:uninstall mymodule
drush config:export
git add config/sync/core.extension.yml config/sync/mymodule.*
git commit -m "Uninstall mymodule"
# Deploy to staging → production. Verify drush config:status is clean everywhere.

# Step 2: only after all environments have imported the config
composer remove drupal/mymodule
git add composer.json composer.lock
git commit -m "Remove mymodule package"
# Deploy. composer install now succeeds — the module isn't referenced in active config.

# Wrong — reverse order, breaks composer install
composer remove drupal/mymodule    # ← class not found on next install