✨ Narrow return value of getKey by whether hasKey was called beforehand (#905)

✨ Narrow return value of getKey by whether hasKey was called beforehand

Co-authored-by: Matt Glaman <[email protected]>

Author: dpi

extension.neon

@@ -290,6 +290,9 @@ services:
 	-
 		class: mglaman\PHPStanDrupal\Type\EntityIdNarrowedByNew
 		tags: [phpstan.broker.dynamicMethodReturnTypeExtension]
+	-
+		class: mglaman\PHPStanDrupal\Type\EntityTypeKeyByExistence
+		tags: [phpstan.broker.dynamicMethodReturnTypeExtension]
 	-
 		class: mglaman\PHPStanDrupal\Type\EntityTypeLinkTemplateByExistence
 		tags: [phpstan.broker.dynamicMethodReturnTypeExtension]

src/Type/EntityTypeKeyByExistence.php

@@ -0,0 +1,52 @@
+<?php declare(strict_types=1);
+
+namespace mglaman\PHPStanDrupal\Type;
+
+use Drupal\Core\Entity\EntityTypeInterface;
+use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Identifier;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Type\Constant\ConstantBooleanType;
+use PHPStan\Type\DynamicMethodReturnTypeExtension;
+use PHPStan\Type\StringType;
+use PHPStan\Type\Type;
+
+/**
+ * @author Daniel Phin <[email protected]>
+ */
+class EntityTypeKeyByExistence implements DynamicMethodReturnTypeExtension
+{
+
+    public function getClass(): string
+    {
+        return EntityTypeInterface::class;
+    }
+
+    public function isMethodSupported(MethodReflection $methodReflection): bool
+    {
+        return $methodReflection->getName() === 'getKey';
+    }
+
+    public function getTypeFromMethodCall(
+        MethodReflection $methodReflection,
+        MethodCall $methodCall,
+        Scope $scope
+    ): ?Type {
+        $keyArg = $methodCall->getArg('key', 0);
+        if (null === $keyArg) {
+            // Key is a required arg but ignore if it isn't set.
+            return null;
+        }
+
+        $originalReturnType = $methodReflection->getVariants()[0]->getReturnType();
+        $hasKeyMethodCall = new MethodCall($methodCall->var, new Identifier('hasKey'), [$keyArg]);
+        if ($scope->getType($hasKeyMethodCall)->isTrue()->yes()) {
+            return $originalReturnType->tryRemove(new ConstantBooleanType(false));
+        } elseif ($scope->getType($hasKeyMethodCall)->isFalse()->yes()) {
+            return $originalReturnType->tryRemove(new StringType());
+        }
+
+        return $originalReturnType;
+    }
+}

tests/src/Type/data/entity-type-stubs.php

@@ -17,6 +17,27 @@ function (ContentEntityInterface $entity): void
     }
 };
 
+assert($entityTypeDefault instanceof EntityType);
+assertType('string|false', $entityTypeDefault->getKey('foo'));
+
+assert($noKey instanceof EntityType);
+assert($noKey->hasKey('foo') === FALSE);
+assertType('false', $noKey->getKey('foo'));
+
+assert($hasKey instanceof EntityType);
+assert($hasKey->hasKey('foo') === TRUE);
+assertType('string', $hasKey->getKey('foo'));
+
+// Test getting a key doesn't affect another key.
+assert($entityType instanceof EntityType);
+assert($entityType->hasKey('foo') === TRUE);
+assertType('string', $entityType->getKey('foo'));
+// A different arg that wasn't narrowed previously:
+assertType('string|false', $entityType->getKey('bar'));
+// ...until we know better:
+assert($entityType->hasKey('bar') === TRUE);
+assertType('string', $entityType->getKey('bar'));
+
 assert($entityTypeDefault instanceof EntityType);
 assertType('string|false', $entityTypeDefault->getLinkTemplate('foo'));