Getting Started

Install the plugin via Composer in your REDAXO project:
```
composer require --dev redaxo/psalm-plugin
```
(Assumes Psalm is already installed; if not, run composer require --dev vimeo/psalm first.)
Enable the plugin in your psalm.xml:
```
<pluginClass class="Redaxo\PsalmPlugin\Plugin"/>
```
No additional config is required—the plugin auto-discovers REDAXO’s structure (e.g., redaxo/src, packages/).
Run your first analysis:
```
./vendor/bin/psalm
```
Expect immediate improvements in type accuracy for REDAXO-specific patterns like rex_backend_login, dynamic rex_package usage, or rex_sql query inference.

Implementation Patterns

Leverage framework-aware stubs without manual overrides:
The plugin injects precise signatures for core classes (rex_backend_login, rex_logger, rex_file, etc.) and add-on APIs (e.g., rex_yrewrite or ystab), so Psalm infers correct return types (e.g., rex_clang objects, arrays of rex_category, etc.).
Analyze dynamic patterns confidently:
Use Psalm’s @psalm-return/@psalm-param annotations alongside REDAXO conventions (e.g., rex_addon::get(), rex_fragment::show()), and the plugin ensures Psalm understands return types even when values are derived from rex_context or rex_request.
Integrate with CI:
Add psalm --output-format=checkstyle > psalm-report.xml to your pipeline; the reduced false positives mean CI reports focus on real issues. For add-on development, set <projectFiles> to scan only /src or /packages/your_package/src.
Extend type safety with custom stubs:
If you maintain a private add-on with complex APIs, use additionalFiles in psalm.xml to include custom stubs—e.g., for custom rex_sql extensions—and the plugin will honor them.

Stubs may lag behind REDAXO core updates:
Check the plugin’s src/Stub/ directory for compatibility with your REDAXO version (≥5.13+). If you spot outdated signatures (e.g., missing rex_clang::getAll() return types), contribute stubs upstream or use <stubs> in psalm.xml as a temporary override.
rex_sql type inference nuances:
While the plugin handles basic rex_sql::factory() → rex_sql, chained methods like ->getValue('foo') may still infer mixed in complex joins. Mitigate by:
```
/** @var string $foo */
$foo = $sql->getValue('foo');
```
or enabling _propertyReferences analysis in psalm.xml.
Avoid rex_addon::load() false negatives:
When using rex_addon::get('yforms'), Psalm now correctly infers rex_yforms_addon (if installed), but only if packages/ is scanned. Ensure psalm.xml includes:
```
<directory name="packages"/>
<directory name="redaxo/src/addons"/>
```
Suppress only REDAXO-specific false positives:
Use @psalm-suppress sparingly. For example, if rex_logger::log()’s mixed $message type bugs you, write:
```
/** @psalm-suppress InvalidArgument */
rex_logger::log('error', ['context' => $e]);
```
...but first verify it’s not a plugin bug (check the plugin’s issue tracker).