From 0bc1217c00318bd8f4352834a83f53e23dea74ee Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Tue, 31 Mar 2026 00:31:34 +0000
Subject: [PATCH] Fix phpstan/phpstan#10231: value-of with OffsetAccessType
 resolving to *ERROR*

- Skip toArrayKey() normalization in TypeNodeResolver when array key type
  is a LateResolvableType, preventing premature resolution and loss of
  type information
- Resolve late-resolvable types after resolveToBounds in TypehintHelper
  decideType check, so the PHPDoc type compatibility check works correctly
- Handle value-of<non-iterable> gracefully in ValueOfType::getResult()
  when the inner type is a LateResolvableType that resolves to a scalar
- New regression test in tests/PHPStan/Analyser/nsrt/bug-10231.php
---
 src/PhpDoc/TypeNodeResolver.php           | 31 +++++++++------
 src/Type/TypehintHelper.php               |  2 +-
 src/Type/ValueOfType.php                  | 10 ++++-
 tests/PHPStan/Analyser/nsrt/bug-10231.php | 48 +++++++++++++++++++++++
 4 files changed, 76 insertions(+), 15 deletions(-)
 create mode 100644 tests/PHPStan/Analyser/nsrt/bug-10231.php

diff --git a/src/PhpDoc/TypeNodeResolver.php b/src/PhpDoc/TypeNodeResolver.php
index 8af74bf9264..8226370d449 100644
--- a/src/PhpDoc/TypeNodeResolver.php
+++ b/src/PhpDoc/TypeNodeResolver.php
@@ -85,6 +85,7 @@
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\IterableType;
 use PHPStan\Type\KeyOfType;
+use PHPStan\Type\LateResolvableType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\NewObjectType;
 use PHPStan\Type\NonAcceptingNeverType;
@@ -678,20 +679,24 @@ static function (string $variance): TemplateTypeVariance {
 			if (count($genericTypes) === 1) { // array<ValueType>
 				$arrayType = new ArrayType(new BenevolentUnionType([new IntegerType(), new StringType()]), $genericTypes[0]);
 			} elseif (count($genericTypes) === 2) { // array<KeyType, ValueType>
-				$keyType = TypeCombinator::intersect($genericTypes[0]->toArrayKey(), new UnionType([
-					new IntegerType(),
-					new StringType(),
-				]))->toArrayKey();
-				$finiteTypes = $keyType->getFiniteTypes();
-				if (
-					count($finiteTypes) === 1
-					&& ($finiteTypes[0] instanceof ConstantStringType || $finiteTypes[0] instanceof ConstantIntegerType)
-				) {
-					$arrayBuilder = ConstantArrayTypeBuilder::createEmpty();
-					$arrayBuilder->setOffsetValueType($finiteTypes[0], $genericTypes[1], true);
-					$arrayType = $arrayBuilder->getArray();
+				if ($genericTypes[0] instanceof LateResolvableType) {
+					$arrayType = new ArrayType($genericTypes[0], $genericTypes[1]);
 				} else {
-					$arrayType = new ArrayType($keyType, $genericTypes[1]);
+					$keyType = TypeCombinator::intersect($genericTypes[0]->toArrayKey(), new UnionType([
+						new IntegerType(),
+						new StringType(),
+					]))->toArrayKey();
+					$finiteTypes = $keyType->getFiniteTypes();
+					if (
+						count($finiteTypes) === 1
+						&& ($finiteTypes[0] instanceof ConstantStringType || $finiteTypes[0] instanceof ConstantIntegerType)
+					) {
+						$arrayBuilder = ConstantArrayTypeBuilder::createEmpty();
+						$arrayBuilder->setOffsetValueType($finiteTypes[0], $genericTypes[1], true);
+						$arrayType = $arrayBuilder->getArray();
+					} else {
+						$arrayType = new ArrayType($keyType, $genericTypes[1]);
+					}
 				}
 			} else {
 				return new ErrorType();
diff --git a/src/Type/TypehintHelper.php b/src/Type/TypehintHelper.php
index 076fedcaccc..7cbb69609b4 100644
--- a/src/Type/TypehintHelper.php
+++ b/src/Type/TypehintHelper.php
@@ -123,7 +123,7 @@ public static function decideType(
 				($type->isCallable()->yes() && $phpDocType->isCallable()->yes())
 				|| (
 					(!$phpDocType instanceof NeverType || ($type instanceof MixedType && !$type->isExplicitMixed()))
-					&& $type->isSuperTypeOf(TemplateTypeHelper::resolveToBounds($phpDocType))->yes()
+					&& $type->isSuperTypeOf(TypeUtils::resolveLateResolvableTypes(TemplateTypeHelper::resolveToBounds($phpDocType)))->yes()
 				)
 			) {
 				$resultType = $phpDocType;
diff --git a/src/Type/ValueOfType.php b/src/Type/ValueOfType.php
index e2d3f0516c2..78657a2438a 100644
--- a/src/Type/ValueOfType.php
+++ b/src/Type/ValueOfType.php
@@ -81,7 +81,15 @@ protected function getResult(): Type
 			return new UnionType($valueTypes);
 		}
 
-		return $this->type->getIterableValueType();
+		$iterableValueType = $this->type->getIterableValueType();
+		if ($iterableValueType instanceof ErrorType && $this->type instanceof LateResolvableType) {
+			$resolvedType = $this->type->resolve();
+			if (!$resolvedType instanceof ErrorType) {
+				return $resolvedType;
+			}
+		}
+
+		return $iterableValueType;
 	}
 
 	/**
diff --git a/tests/PHPStan/Analyser/nsrt/bug-10231.php b/tests/PHPStan/Analyser/nsrt/bug-10231.php
new file mode 100644
index 00000000000..243f2432f39
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-10231.php
@@ -0,0 +1,48 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug10231;
+
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+	/**
+	 * @template TGroupColumnName of array-key
+	 * @template TValueColumnName of array-key
+	 * @template TArray of array
+	 * @param array<TArray> $input
+	 * @param TGroupColumnName $groupByColumn
+	 * @param TValueColumnName $valueColumnName
+	 *
+	 * @return array<
+	 *   value-of<TArray[TGroupColumnName]>,
+	 *   list<value-of<TArray[TValueColumnName]>>
+	 * >
+	 */
+	public static function groupByColumn(array $input, string|int $groupByColumn, string|int $valueColumnName): array
+	{
+		$output = [];
+		foreach ($input as $result) {
+			$output[$result[$groupByColumn]][] = $result[$valueColumnName];
+		}
+
+		return $output;
+	}
+}
+
+/** @var array<array{event_id: string, id: int}> $input */
+$input = [
+	['event_id' => '111', 'id' => 1],
+	['event_id' => '111', 'id' => 2],
+	['event_id' => '222', 'id' => 99],
+];
+
+$result = HelloWorld::groupByColumn(
+	$input,
+	'event_id',
+	'id',
+);
+
+assertType('array<string, list<int>>', $result);