From 38409e5f97c983807bfdc947d2e943d265055833 Mon Sep 17 00:00:00 2001
From: Wleeaf <179125857+wleeaf@users.noreply.github.com>
Date: Sun, 25 Oct 2026 16:06:24 +0000
Subject: [PATCH] fix: keep & on foreach targets that are not plain variables

foreach can assign by reference to a property, an array element or a
static property, not just to a variable. The parser marks such a value
with byref, but only the variable printer prints the &, so

    foreach ($test as $key => &$array[$key]) {}

was formatted as `foreach ($test as $key => $array[$key]) {}`, which
assigns by value and silently changes what the loop does.

The foreach printer now adds the & itself for a byref value that is not
a variable.
---
 src/printer.mjs                                 |  9 +++++++--
 tests/foreach/__snapshots__/jsfmt.spec.mjs.snap | 12 ++++++++++++
 tests/foreach/foreach.php                       |  6 ++++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/printer.mjs b/src/printer.mjs
index a9f06c170..2a00cb2ce 100644
--- a/src/printer.mjs
+++ b/src/printer.mjs
@@ -2063,6 +2063,11 @@ function printNode(path, options, print) {
     }
     case "foreach": {
       const body = printBodyControlStructure(path, options, print, "body");
+      // Only a plain variable prints its own &
+      const value =
+        node.value.byref && node.value.kind !== "variable"
+          ? ["&", print("value")]
+          : print("value");
 
       // We want to keep dangling comments above the loop to stay consistent.
       // Any comment positioned between the for statement and the parentheses
@@ -2086,8 +2091,8 @@ function printNode(path, options, print) {
               "as ",
               group(
                 node.key
-                  ? indent(join([" =>", line], [print("key"), print("value")]))
-                  : print("value")
+                  ? indent(join([" =>", line], [print("key"), value]))
+                  : value
               ),
             ]),
             softline,
diff --git a/tests/foreach/__snapshots__/jsfmt.spec.mjs.snap b/tests/foreach/__snapshots__/jsfmt.spec.mjs.snap
index 1b0055a93..af79ba8c9 100644
--- a/tests/foreach/__snapshots__/jsfmt.spec.mjs.snap
+++ b/tests/foreach/__snapshots__/jsfmt.spec.mjs.snap
@@ -72,6 +72,12 @@ foreach ($test as &$i) {
     $test2 = $i;
 }
 
+foreach ($test as &$object->property) {
+}
+
+foreach ($test as $key => &$array[$key]) {
+}
+
 =====================================output=====================================
 <?php
 foreach ($test as $i) {
@@ -170,5 +176,11 @@ foreach ($test as &$i) {
     $test2 = $i;
 }
 
+foreach ($test as &$object->property) {
+}
+
+foreach ($test as $key => &$array[$key]) {
+}
+
 ================================================================================
 `;
diff --git a/tests/foreach/foreach.php b/tests/foreach/foreach.php
index f6ffdfc94..b2e368e45 100644
--- a/tests/foreach/foreach.php
+++ b/tests/foreach/foreach.php
@@ -63,3 +63,9 @@
 foreach ($test as &$i) {
     $test2 = $i;
 }
+
+foreach ($test as &$object->property) {
+}
+
+foreach ($test as $key => &$array[$key]) {
+}