Automated testing is an essential part of any software upgrade, and it's great that you are considering it for your PHP upgrade. While it is feasible to use a script to read through your PHP code base and look for deprecated and incompatible features from PHP 8 release notes, it may not be a comprehensive solution.
There are several types of automated tests that you can use to ensure that your PHP 8 upgrade works correctly. Some of them include unit tests, integration tests, and system tests. Unit tests test individual units or modules of your code, while integration tests check the interaction between different components of your application. System tests test the application as a whole and its behavior under different conditions.
In addition to these tests, you can also use tools such as
PHPMD to analyse your code and identify any issues that might arise during the upgrade.
To make your testing more comprehensive, you can also consider manual testing in addition to automated testing. Manual testing can help you identify issues that might not be caught by automated tests, such as issues with user interface or user experience.
Overall, using a script to identify deprecated and incompatible features from
PHP 8 release notes can be a good starting point, but it's important to consider other types of tests and tools to ensure a successful upgrade.