Stop PHPDoc arrays with specified key type being converted to iterables when the native type is iterable

Author: ondrejmirtes

phpstan-baseline.neon

@@ -1812,7 +1812,7 @@ parameters:
 		-
 			message: '#^Doing instanceof PHPStan\\Type\\Constant\\ConstantArrayType is error\-prone and deprecated\. Use Type\:\:getConstantArrays\(\) instead\.$#'
 			identifier: phpstanApi.instanceofType
-			count: 3
+			count: 1
 			path: src/Type/TypehintHelper.php
 
 		-

src/Type/TypehintHelper.php

@@ -101,7 +101,7 @@ public static function decideType(
 				if ($phpDocType instanceof UnionType) {
 					$innerTypes = [];
 					foreach ($phpDocType->getTypes() as $innerType) {
-						if ($innerType instanceof ArrayType || $innerType instanceof ConstantArrayType) {
+						if ($innerType instanceof ArrayType && $innerType->getKeyType()->describe(VerbosityLevel::typeOnly()) === 'mixed') {
 							$innerTypes[] = new IterableType(
 								$innerType->getIterableKeyType(),
 								$innerType->getItemType(),
@@ -111,7 +111,7 @@ public static function decideType(
 						}
 					}
 					$phpDocType = new UnionType($innerTypes);
-				} elseif ($phpDocType instanceof ArrayType || $phpDocType instanceof ConstantArrayType) {
+				} elseif ($phpDocType instanceof ArrayType && $phpDocType->getKeyType()->describe(VerbosityLevel::typeOnly()) === 'mixed') {
 					$phpDocType = new IterableType(
 						$phpDocType->getKeyType(),
 						$phpDocType->getItemType(),

tests/PHPStan/Analyser/nsrt/bug-13411.php

@@ -0,0 +1,17 @@
+<?php declare(strict_types = 1);
+
+namespace Bug13411;
+
+use SplFixedArray;
+use function PHPStan\Testing\assertType;
+
+class Token {}
+
+/** @extends SplFixedArray<Token> */
+class Tokens extends SplFixedArray {}
+
+/** @param array<int, Token>|Tokens $tokens */
+function x(iterable $tokens): int {
+	assertType('array<int, Bug13411\\Token>|Bug13411\\Tokens', $tokens);
+	return count($tokens);
+}