Better "missing iterable value type" for unsealed types

Author: ondrejmirtes

src/Rules/MissingTypehintCheck.php

@@ -14,6 +14,7 @@
 use PHPStan\Type\ClosureType;
 use PHPStan\Type\ConditionalType;
 use PHPStan\Type\ConditionalTypeForParameter;
+use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Generic\GenericObjectType;
 use PHPStan\Type\Generic\GenericStaticType;
 use PHPStan\Type\Generic\TemplateType;
@@ -23,6 +24,7 @@
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverser;
+use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
 use Traversable;
 use function array_filter;
@@ -88,6 +90,26 @@ public function getIterableTypesWithMissingValueTypehint(Type $type): array
 				return $type;
 			}
 			if ($type->isIterable()->yes()) {
+				if ($type->isConstantArray()->yes()) {
+					$type = TypeTraverser::map($type, static function (Type $type, callable $traverse) use (&$descriptions) {
+						if ($type instanceof UnionType || $type instanceof IntersectionType) {
+							return $traverse($type);
+						}
+
+						if ($type instanceof ConstantArrayType) {
+							$unsealed = $type->getUnsealedTypes();
+							if ($unsealed !== null) {
+								$iterableUnsealedValue = $unsealed[1];
+								if ($iterableUnsealedValue instanceof MixedType && !$iterableUnsealedValue->isExplicitMixed()) {
+									$descriptions[] = 'unsealed extra keys (...)';
+								}
+								return $traverse($type->dropUnsealedTypes());
+							}
+						}
+
+						return $traverse($type);
+					});
+				}
 				$iterableValue = $type->getIterableValueType();
 				if ($iterableValue instanceof MixedType && !$iterableValue->isExplicitMixed()) {
 					$descriptions[] = sprintf('iterable type %s', $type->describe(VerbosityLevel::typeOnly()));

src/Type/Constant/ConstantArrayType.php

@@ -190,6 +190,21 @@ public function getUnsealedTypes(): ?array
 		return $this->unsealed;
 	}
 
+	/**
+	 * @internal
+	 */
+	public function dropUnsealedTypes(): self
+	{
+		return $this->recreate(
+			$this->keyTypes,
+			$this->valueTypes,
+			$this->nextAutoIndexes,
+			$this->optionalKeys,
+			$this->isList,
+			null,
+		);
+	}
+
 	/**
 	 * @param list<ConstantIntegerType|ConstantStringType> $keyTypes
 	 * @param array<int, Type> $valueTypes

tests/PHPStan/Rules/Methods/MissingMethodParameterTypehintRuleTest.php

@@ -86,6 +86,16 @@ public function testRule(): void
 				'Method MissingMethodParameterTypehint\Baz::acceptsGenericWithSomeDefaults() has parameter $c with generic class MissingMethodParameterTypehint\GenericClassWithSomeDefaults but does not specify its types: T, U (1-2 required)',
 				270,
 			],
+			[
+				'Method MissingMethodParameterTypehint\UnsealedArrayShape::doFoo() has parameter $a with no value type specified in unsealed extra keys (...).',
+				284,
+				MissingTypehintCheck::MISSING_ITERABLE_VALUE_TYPE_TIP,
+			],
+			[
+				'Method MissingMethodParameterTypehint\UnsealedArrayShape::doBar() has parameter $a with no value type specified in unsealed extra keys (...).',
+				293,
+				MissingTypehintCheck::MISSING_ITERABLE_VALUE_TYPE_TIP,
+			],
 		];
 
 		$this->analyse([__DIR__ . '/data/missing-method-parameter-typehint.php'], $errors);

tests/PHPStan/Rules/Methods/data/missing-method-parameter-typehint.php

@@ -273,3 +273,26 @@ public function acceptsGenericWithSomeDefaults(GenericClassWithSomeDefaults $c)
 	}
 
 }
+
+class UnsealedArrayShape
+{
+
+	/**
+	 * @param array{a: int, ...} $a
+	 * @param array{a: int, ...<mixed>} $b
+	 */
+	public function doFoo(array $a, array $b): void
+	{
+
+	}
+
+	/**
+	 * @param non-empty-array{a?: int, b?: int, ...} $a
+	 * @param non-empty-array{a?: int, b?: int, ...<mixed>} $b
+	 */
+	public function doBar(array $a, array $b): void
+	{
+
+	}
+
+}