{ "uuid": [ { "value": "01893784-8f45-4466-8586-17df23e7e4b5" } ], "langcode": [ { "value": "en" } ], "type": [ { "target_id": "daily_email", "target_type": "node_type", "target_uuid": "8bde1f2f-eef9-4f2d-ae9c-96921f8193d7" } ], "revision_timestamp": [ { "value": "2025-05-11T09:00:00+00:00" } ], "revision_uid": [ { "target_type": "user", "target_uuid": "b8966985-d4b2-42a7-a319-2e94ccfbb849" } ], "revision_log": [], "status": [ { "value": true } ], "uid": [ { "target_type": "user", "target_uuid": "b8966985-d4b2-42a7-a319-2e94ccfbb849" } ], "title": [ { "value": "What's the correct way to add PHPStan to an existing codebase?" } ], "created": [ { "value": "2025-03-16T00:00:00+00:00" } ], "changed": [ { "value": "2025-05-11T09:00:00+00:00" } ], "promote": [ { "value": false } ], "sticky": [ { "value": false } ], "default_langcode": [ { "value": true } ], "revision_translation_affected": [ { "value": true } ], "path": [ { "alias": "\/daily\/2025\/03\/16\/what-s-the-correct-way-to-add-phpstan-to-an-existing-codebase", "langcode": "en" } ], "body": [ { "value": "\n

PHPStan is a static analysis tool for PHP.<\/p>\n\n

It finds potential issues in PHP code without needing to run it, so Developers can find and resolve potential issues sooner.<\/p>\n\n

I use it on all my projects including existing ones I've inherited.<\/p>\n\n

But how can you add a static analysis tool to a codebase without getting a lot of errors from the existing code?<\/p>\n\n

PHPStan has different levels of strictness.<\/p>\n\n

Level 0 is the least strict and each level adds more rules and strictness, resulting in more errors.<\/p>\n\n

Most of the time, people will start by running PHPStan on level 0, fixing any errors and committing the changes.<\/p>\n\n

Then repeat the process as many times as needed until you reach the level you want to achieve.<\/p>\n\n

I don't think this is the right approach.<\/p>\n\n

This could mean that you need to edit the same files multiple times as you work through the levels.<\/p>\n\n

There's also a period of time where Developers can still write suboptimal code whilst you work your way up to your desired level.<\/p>\n\n

Another approach is to use a feature of PHPStan called the baseline.<\/p>\n\n

The baseline is a way of capturing and saving all the existing errors up to the selected level so they are no longer reported.<\/p>\n\n

If you did this for an existing project, it would return no errors as everything would be included in the baseline.<\/p>\n\n

Once you decide what level you want your project to run, you can start as soon as the baseline is generated and without needing to change files multiple times.<\/p>\n\n

Instead of spending time working through the levels one at a time, commit some time to pruning the baseline and reducing the errors in it.<\/p>\n\n

This I think is a better approach and how I add PHPStan to existing codebases.<\/p>\n\n

To learn more about static analysis and PHPStan, listen to episode 22 of the Beyond Blocks podcast<\/a> with Dave Liddament.<\/p>\n\n ", "format": "full_html", "processed": "\n

PHPStan is a static analysis tool for PHP.<\/p>\n\n

It finds potential issues in PHP code without needing to run it, so Developers can find and resolve potential issues sooner.<\/p>\n\n

I use it on all my projects including existing ones I've inherited.<\/p>\n\n

But how can you add a static analysis tool to a codebase without getting a lot of errors from the existing code?<\/p>\n\n

PHPStan has different levels of strictness.<\/p>\n\n

Level 0 is the least strict and each level adds more rules and strictness, resulting in more errors.<\/p>\n\n

Most of the time, people will start by running PHPStan on level 0, fixing any errors and committing the changes.<\/p>\n\n

Then repeat the process as many times as needed until you reach the level you want to achieve.<\/p>\n\n

I don't think this is the right approach.<\/p>\n\n

This could mean that you need to edit the same files multiple times as you work through the levels.<\/p>\n\n

There's also a period of time where Developers can still write suboptimal code whilst you work your way up to your desired level.<\/p>\n\n

Another approach is to use a feature of PHPStan called the baseline.<\/p>\n\n

The baseline is a way of capturing and saving all the existing errors up to the selected level so they are no longer reported.<\/p>\n\n

If you did this for an existing project, it would return no errors as everything would be included in the baseline.<\/p>\n\n

Once you decide what level you want your project to run, you can start as soon as the baseline is generated and without needing to change files multiple times.<\/p>\n\n

Instead of spending time working through the levels one at a time, commit some time to pruning the baseline and reducing the errors in it.<\/p>\n\n

This I think is a better approach and how I add PHPStan to existing codebases.<\/p>\n\n

To learn more about static analysis and PHPStan, listen to episode 22 of the Beyond Blocks podcast<\/a> with Dave Liddament.<\/p>\n\n ", "summary": null } ] }