TYPO3 Extension Upgrade Skill

Systematic framework for upgrading TYPO3 extensions to newer LTS versions.

Scope: Extension code upgrades only. NOT for TYPO3 project/core upgrades.

Upgrade Toolkit

Tool	Purpose	Files
Extension Scanner	Diagnose deprecated APIs	TYPO3 Backend
Rector	Automated PHP migrations	.php
Fractor	Non-PHP migrations	FlexForms, TypoScript, YAML, Fluid
PHPStan	Static analysis	.php

Core Workflow

1. Complete planning phase (consult references/pre-upgrade.md)
2. Create feature branch (verify git is clean)
3. Update composer.json constraints for target version
4. Run rector process --dry-run then review and apply
5. Run fractor process --dry-run then review and apply
6. Run php-cs-fixer fix
7. Run phpstan analyse and fix errors
8. Run phpunit and fix tests
9. Test in target TYPO3 version(s)
10. Verify success criteria (consult references/verification.md)

When NOT to Apply Automatically

Do NOT blindly apply Rector/Fractor if:

• You need dual-version compatibility (v12 + v13)
• The extension has no tests to verify changes
• The diff shows changes you don't understand
• The rule affects complex APIs (DBAL, Extbase internals)

Instead: apply specific rules manually, test between each change.

Quick Commands

# Rector: automated PHP migrations
./vendor/bin/rector process --dry-run && ./vendor/bin/rector process

# Fractor: non-PHP migrations
./vendor/bin/fractor process --dry-run && ./vendor/bin/fractor process

# Quality checks
./vendor/bin/php-cs-fixer fix && ./vendor/bin/phpstan analyse && ./vendor/bin/phpunit

TYPO3 Changelogs

Version	Changelog
v14	Changelog-14
v13	Changelog-13
v12	Changelog-12

Asset Templates

Configure tooling by copying and adjusting these templates:

• assets/rector.php - Rector configuration for PHP migrations
• assets/fractor.php - Fractor configuration for non-PHP migrations
• assets/phpstan.neon - PHPStan static analysis configuration
• assets/phpunit.xml - PHPUnit test configuration
• assets/.php-cs-fixer.php - PHP-CS-Fixer code style configuration

References

Reference	Use when...
references/pre-upgrade.md	Starting an upgrade: planning checklist, version audit, risk assessment
references/api-changes.md	Checking deprecated/removed APIs by TYPO3 version
references/upgrade-v11-to-v12.md	Upgrading from TYPO3 v11 to v12
references/upgrade-v12-to-v13.md	Upgrading from TYPO3 v12 to v13
references/dual-compatibility.md	Maintaining dual compatibility (v12 + v13)
references/real-world-patterns.md	Looking for real-world migration examples
references/toolchain-output.md	Understanding Rector/Fractor dry-run output
references/troubleshooting.md	Rector broke code, PHPStan errors, test failures
references/verification.md	Checking success criteria and real-world testing

External Resources

• TYPO3 Rector Documentation
• Fractor Documentation
• TYPO3 Core Changelog

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Contributing: https://github.com/netresearch/typo3-extension-upgrade-skill