Do not report generic covariant issue without strict check

Author: VincentLanglet

src/Rules/PhpDoc/VarTagTypeRuleHelper.php

@@ -18,10 +18,12 @@
 use PHPStan\Type\ArrayType;
 use PHPStan\Type\FileTypeMapper;
 use PHPStan\Type\Generic\GenericObjectType;
+use PHPStan\Type\Generic\TemplateTypeVariance;
 use PHPStan\Type\IsSuperTypeOfResult;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\Type;
+use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\TypeUtils;
 use PHPStan\Type\VerbosityLevel;
 use function array_key_exists;
@@ -182,6 +184,17 @@ private function isValidSuperType(Scope $scope, Type $type, Type $varTagType, in
 			return $this->isSuperTypeOfVarType($scope, $type, $varTagType);
 		}
 
+		$type = TypeTraverser::map($type, static function (Type $type, callable $traverse): Type {
+			if ($type instanceof GenericObjectType) {
+				$type = $type->changeVariances(array_map(
+					static fn (TemplateTypeVariance $variance) => $variance->invariant() ? TemplateTypeVariance::createCovariant() : $variance,
+					$type->getVariances(),
+				));
+			}
+
+			return $traverse($type);
+		});
+
 		if ($type->isConstantArray()->yes()) {
 			if ($type->isIterableAtLeastOnce()->no()) {
 				$type = new ArrayType(new MixedType(), new MixedType());

src/Type/Generic/GenericObjectType.php

@@ -403,6 +403,14 @@ protected function recreate(string $className, array $types, ?Type $subtractedTy
 		);
 	}
 
+	/**
+	 * @param TemplateTypeVariance[] $variances
+	 */
+	public function changeVariances(array $variances): self
+	{
+		return $this->recreate($this->getClassName(), $this->getTypes(), $this->getSubtractedType(), $variances);
+	}
+
 	public function changeSubtractedType(?Type $subtractedType): Type
 	{
 		$result = parent::changeSubtractedType($subtractedType);

tests/PHPStan/Rules/PhpDoc/WrongVariableNameInVarTagRuleTest.php

@@ -586,7 +586,7 @@ public function testBug12457(): void
 		]);
 	}
 
-	public function testGenericSubtype(): void
+	public function testGenericSubtypeWithStrictCheck(): void
 	{
 		$this->checkTypeAgainstPhpDocType = true;
 		$this->strictWideningCheck = true;
@@ -604,6 +604,13 @@ public function testGenericSubtype(): void
 		]);
 	}
 
+	public function testGenericSubtypeWithoutStrictCheck(): void
+	{
+		$this->checkTypeAgainstPhpDocType = true;
+		$this->strictWideningCheck = false;
+		$this->analyse([__DIR__ . '/data/generic-subtype.php'], []);
+	}
+
 	public function testNewIsAlwaysFinalClass(): void
 	{
 		$this->checkTypeAgainstPhpDocType = true;