Fastest way to upgrade laravel 5.2 app to laravel 9

Upgrading a Laravel application from version 5.2 to 9.0 is a significant task due to the multiple major version changes, each introducing breaking changes, new features, and deprecations. Here’s a step-by-step guide to help you upgrade efficiently:

1. Understand the Upgrade Path

• Laravel 5.2 → 5.5 → 5.8 → 6.x (LTS) → 7.x → 8.x → 9.x
• You need to upgrade incrementally through these versions, as Laravel doesn’t support skipping major versions directly.

2. Backup Your Application

• Before starting the upgrade, make sure to back up your entire application, including the database. This will ensure you can revert if something goes wrong.

3. Upgrade Step-by-Step

• Upgrade to Laravel 5.5:
  • Update your composer.json to require "laravel/framework": "5.5.*".
  • Run composer update.
  • Follow the Laravel 5.5 upgrade guide for specific changes, such as middleware updates, blade directives, etc.
• Upgrade to Laravel 5.8:
  • Update your composer.json to require "laravel/framework": "5.8.*".
  • Run composer update.
  • Follow the Laravel 5.8 upgrade guide.
• Upgrade to Laravel 6.x (LTS):
  • Update your composer.json to require "laravel/framework": "^6.0".
  • Run composer update.
  • Follow the Laravel 6.x upgrade guide.
• Upgrade to Laravel 7.x:
  • Update your composer.json to require "laravel/framework": "^7.0".
  • Run composer update.
  • Follow the Laravel 7.x upgrade guide.
• Upgrade to Laravel 8.x:
  • Update your composer.json to require "laravel/framework": "^8.0".
  • Run composer update.
  • Follow the Laravel 8.x upgrade guide.
• Upgrade to Laravel 9.x:
  • Update your composer.json to require "laravel/framework": "^9.0".
  • Run composer update.
  • Follow the Laravel 9.x upgrade guide.

4. Testing After Each Upgrade

• After upgrading to each version, run your test suite (phpunit) to ensure that everything is working as expected.
• Manually test critical paths of your application to catch any issues not covered by automated tests.

5. Update Dependencies

• Check your composer.json file for any packages that may need to be updated as you upgrade Laravel. Some packages may not be compatible with newer Laravel versions.
• Use composer outdated to see which packages need updates.

6. Check for Deprecated Features

• Review the release notes for each version you upgrade to for deprecated features and remove or replace them in your application.

7. Refactor Code Where Necessary

• Refactor code to adhere to new features, methods, and practices introduced in each version. Laravel documentation provides guidance on changes required.

8. Utilize Laravel Shift

• Laravel Shift is a paid service that can automate the upgrade process for you. It’s especially useful if you’re upgrading across multiple versions and want to save time.
• Visit Laravel Shift for more details.

9. Final Testing

• Once you’ve reached Laravel 9.x, thoroughly test your application, including all major workflows, to ensure that everything works as expected.
• Consider using a staging environment that mirrors production to catch any environment-specific issues.

10. Deploy the Upgrade

• Once confident, deploy the upgraded application to production. Monitor for any issues that arise and be ready to roll back if necessary.

By following this structured approach, you can efficiently upgrade your Laravel application while minimizing potential issues.