isset() narrows string-key in int-keyed-array to numeric-string

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -821,7 +821,7 @@ public function specifyTypesInCondition(
 						);
 					} else {
 						$varType = $scope->getType($var->var);
-						$narrowedKey = AllowedArrayKeysTypes::narrowOffsetKeyType($varType);
+						$narrowedKey = AllowedArrayKeysTypes::narrowOffsetKeyType($varType, $dimType);
 						if ($narrowedKey !== null) {
 							$types = $types->unionWith(
 								$this->create(

src/Rules/Arrays/AllowedArrayKeysTypes.php

@@ -32,7 +32,8 @@ public static function getType(): Type
 		]);
 	}
 
-	public static function narrowOffsetKeyType(Type $varType): ?Type {
+	public static function narrowOffsetKeyType(Type $varType, Type $keyType): ?Type
+	{
 		if (!$varType->isArray()->yes() || $varType->isIterableAtLeastOnce()->no()) {
 			return null;
 		}
@@ -66,17 +67,20 @@ public static function narrowOffsetKeyType(Type $varType): ?Type {
 			if (!$varIterableKeyType->isNumericString()->no() || !$varIterableKeyType->isInteger()->no()) {
 				$narrowedKey = TypeCombinator::union($narrowedKey, new FloatType());
 			}
-		} else {
-			$narrowedKey = new MixedType(
-				false,
-				new UnionType([
-					new ArrayType(new MixedType(), new MixedType()),
-					new ObjectWithoutClassType(),
-					new ResourceType(),
-				]),
-			);
+
+			return $narrowedKey;
+		} elseif ($varIterableKeyType->isInteger()->yes() && $keyType->isString()->yes()) {
+			return TypeCombinator::intersect($varIterableKeyType->toString(), $keyType);
 		}
 
-		return $narrowedKey;
+		return new MixedType(
+			false,
+			new UnionType([
+				new ArrayType(new MixedType(), new MixedType()),
+				new ObjectWithoutClassType(),
+				new ResourceType(),
+			]),
+		);
 	}
+
 }

tests/PHPStan/Analyser/nsrt/bug-11716.php

@@ -35,9 +35,10 @@ public function parse(string $glue): string
 }
 
 /**
- * @param array<int, string> $arr
+ * @param array<int, string> $intKeyedArr
+ * @param array<string, string> $stringKeyedArr
  */
-function narrowKey($mixed, string $s, int $i, array $generalArr, array $arr): void {
+function narrowKey($mixed, string $s, int $i, array $generalArr, array $intKeyedArr, array $stringKeyedArr): void {
 	if (isset($generalArr[$mixed])) {
 		assertType('mixed~(array|object|resource)', $mixed);
 	} else {
@@ -59,21 +60,42 @@ function narrowKey($mixed, string $s, int $i, array $generalArr, array $arr): vo
 	}
 	assertType('string', $s);
 
-	if (isset($arr[$mixed])) {
+	if (isset($intKeyedArr[$mixed])) {
 		assertType('mixed~(array|object|resource)', $mixed);
 	} else {
 		assertType('mixed', $mixed);
 	}
 	assertType('mixed', $mixed);
 
-	if (isset($arr[$i])) {
+	if (isset($intKeyedArr[$i])) {
 		assertType('int', $i);
 	} else {
 		assertType('int', $i);
 	}
 	assertType('int', $i);
 
-	if (isset($arr[$s])) {
+	if (isset($intKeyedArr[$s])) {
+		assertType("numeric-string", $s);
+	} else {
+		assertType('string', $s);
+	}
+	assertType('string', $s);
+
+	if (isset($stringKeyedArr[$mixed])) {
+		assertType('mixed~(array|object|resource)', $mixed);
+	} else {
+		assertType('mixed', $mixed);
+	}
+	assertType('mixed', $mixed);
+
+	if (isset($stringKeyedArr[$i])) {
+		assertType('int', $i);
+	} else {
+		assertType('int', $i);
+	}
+	assertType('int', $i);
+
+	if (isset($stringKeyedArr[$s])) {
 		assertType('string', $s);
 	} else {
 		assertType('string', $s);