Drupal core's static analysis with PHPStan now runs at level 3. It was previously running at level 1.
Levels are cumulative. Moving from 1 to 3 adds these checks:
- Level 2: unknown methods checked on all expressions (not just
$this), validating PHPDocs - Level 3: return types, types assigned to properties
Existing errors at the new level are recorded in core/.phpstan-baseline.php. If an MR introduces a new PHPStan error, fix the code. Don't add the error to the baseline.
For contributed modules, this affects you only if you run core's phpstan.neon.dist, or copy its settings into your own config, to analyze your own code. Core's PHPStan config isn't loaded by anything at runtime. To match core, set level: 3 in your own phpstan.neon. Expect new errors, mainly missing or wrong return types, calls to methods that don't exist on the inferred type, and assignments that don't match a property's type. Fix them, or generate your own baseline with phpstan analyse --generate-baseline.
