Fix phpstan/phpstan#13247: iterable is equal to array|Traversable

phpstan-baseline.neon

@@ -1788,7 +1788,7 @@ parameters:
 		-
 			rawMessage: 'Doing instanceof PHPStan\Type\IterableType is error-prone and deprecated. Use Type::isIterable() instead.'
 			identifier: phpstanApi.instanceofType
-			count: 1
+			count: 3
 			path: src/Type/UnionType.php
 
 		-

src/Type/IterableType.php

@@ -136,13 +136,7 @@ private function isNestedTypeSuperTypeOf(Type $a, Type $b): IsSuperTypeOfResult
 	public function isSubTypeOf(Type $otherType): IsSuperTypeOfResult
 	{
 		if ($otherType instanceof IntersectionType || $otherType instanceof UnionType) {
-			return $otherType->isSuperTypeOf(new UnionType([
-				new ArrayType($this->keyType, $this->itemType),
-				new IntersectionType([
-					new ObjectType(Traversable::class),
-					$this,
-				]),
-			]));
+			return $otherType->isSuperTypeOf($this->toArrayOrTraversable());
 		}
 
 		if ($otherType instanceof self) {
@@ -231,6 +225,17 @@ public function toArray(): Type
 		return new ArrayType($this->keyType, $this->getItemType());
 	}
 
+	public function toArrayOrTraversable(): Type
+	{
+		return new UnionType([
+			new ArrayType($this->keyType, $this->itemType),
+			new GenericObjectType(Traversable::class, [
+				$this->keyType,
+				$this->itemType,
+			]),
+		]);
+	}
+
 	public function toArrayKey(): Type
 	{
 		return new ErrorType();

src/Type/UnionType.php

@@ -194,6 +194,10 @@ public function getConstantStrings(): array
 
 	public function accepts(Type $type, bool $strictTypes): AcceptsResult
 	{
+		if ($type instanceof IterableType) {
+			return $this->accepts($type->toArrayOrTraversable(), $strictTypes);
+		}
+
 		foreach (self::EQUAL_UNION_CLASSES as $baseClass => $classes) {
 			if (!$type->equals(new ObjectType($baseClass))) {
 				continue;
@@ -1073,6 +1077,10 @@ public function toCoercedArgumentType(bool $strictTypes): Type
 
 	public function inferTemplateTypes(Type $receivedType): TemplateTypeMap
 	{
+		if ($receivedType instanceof IterableType) {
+			$receivedType = $receivedType->toArrayOrTraversable();
+		}
+
 		$types = TemplateTypeMap::createEmpty();
 		if ($receivedType instanceof UnionType) {
 			$myTypes = [];

tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php

@@ -2741,4 +2741,9 @@ public function testBug12363(): void
 		$this->analyse([__DIR__ . '/data/bug-12363.php'], []);
 	}
 
+	public function testBug13247(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-13247.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Functions/data/bug-13247.php

@@ -0,0 +1,95 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug13247;
+
+use Traversable;
+
+/**
+ * @template K as array-key
+ * @template V
+ *
+ * @param array<K, V>|Traversable<K, V> $input
+ *
+ * @return array<K, V>
+ */
+function as_array(array|Traversable $input): array {
+	return iter_as_array($input);
+}
+
+/**
+ * @template K as array-key
+ * @template V
+ *
+ * @param iterable<K, V> $input
+ *
+ * @return array<K, V>
+ */
+function iter_as_array(iterable $input): array {
+	return as_array($input);
+}
+
+/**
+ * @param array|Traversable $input
+ *
+ * @return array
+ */
+function as_array2(array|Traversable $input): array {
+	return iter_as_array2($input);
+}
+
+/**
+ * @param iterable $input
+ *
+ * @return array
+ */
+function iter_as_array2(iterable $input): array {
+	return as_array2($input);
+}
+
+/**
+ * @param array<int, int>|Traversable<int, int> $input
+ *
+ * @return array<int, int>
+ */
+function as_array3(array|Traversable $input): array {
+	return iter_as_array3($input);
+}
+
+/**
+ * @param iterable<int, int> $input
+ *
+ * @return array<int, int>
+ */
+function iter_as_array3(iterable $input): array {
+	return as_array3($input);
+}
+
+/**
+ * @phpstan-template T of iterable<int, int>
+ *
+ * @param T $input
+ *
+ * @return mixed
+ */
+function test1(iterable $input) {
+	test2($input);
+	iter_as_array($input);
+
+	return as_array($input);
+}
+
+/**
+ * @phpstan-template U of Traversable<int, int>|array<int, int>
+ *
+ * @param U $input
+ *
+ * @return mixed
+ */
+function test2($input) {
+	test1($input);
+	iter_as_array($input);
+
+	return as_array($input);
+}