From 931e74e9ecf932be77728bcb78531a24edec9541 Mon Sep 17 00:00:00 2001
From: Tomas Votruba <tomas.vot@gmail.com>
Date: Fri, 30 Oct 2026 17:36:39 +0100
Subject: [PATCH] Space compound-assignment operators in blink
 binary_operator_spaces

---
 .../fixer/rules/binary_operator_spaces.go        | 16 +++++++++++++++-
 .../rules/binary_operator_spaces_config_test.go  |  2 ++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/blink/internal/fixer/rules/binary_operator_spaces.go b/blink/internal/fixer/rules/binary_operator_spaces.go
index f0da086189..574ccb2a61 100644
--- a/blink/internal/fixer/rules/binary_operator_spaces.go
+++ b/blink/internal/fixer/rules/binary_operator_spaces.go
@@ -191,7 +191,7 @@ func (f BinaryOperatorSpaces) modeAt(s *tokens.Stream, i int) string {
 		}
 		return ""
 	}
-	if !legacy {
+	if !legacy && !binaryOperatorSpacesCompoundAssign(t.Value) {
 		return ""
 	}
 	if f.Default == "" {
@@ -200,6 +200,17 @@ func (f BinaryOperatorSpaces) modeAt(s *tokens.Stream, i int) string {
 	return f.Default
 }
 
+// binaryOperatorSpacesCompoundAssign reports the compound assignment operators.
+// They are always binary, so they follow the default mode like "=", even without
+// an explicit operators override (matching php-cs-fixer).
+func binaryOperatorSpacesCompoundAssign(op string) bool {
+	switch op {
+	case "+=", "-=", "*=", "/=", ".=", "%=", "**=", "??=", "&=", "|=", "^=", "<<=", ">>=":
+		return true
+	}
+	return false
+}
+
 func binaryOperatorSpacesDefaultTarget(s *tokens.Stream, i int) bool {
 	t := s.At(i)
 	if t.Kind != token.Punct {
@@ -217,6 +228,9 @@ func binaryOperatorSpacesDefaultTarget(s *tokens.Stream, i int) bool {
 // may only be spaced when explicitly configured through the operators option.
 func binaryOperatorSpacesExtraTarget(s *tokens.Stream, i int) bool {
 	t := s.At(i)
+	if binaryOperatorSpacesCompoundAssign(t.Value) {
+		return true
+	}
 	switch t.Value {
 	case "**", "/", "%", "^", "<<", ">>":
 		return true
diff --git a/blink/internal/fixer/rules/binary_operator_spaces_config_test.go b/blink/internal/fixer/rules/binary_operator_spaces_config_test.go
index f2017c45a8..632a90394b 100644
--- a/blink/internal/fixer/rules/binary_operator_spaces_config_test.go
+++ b/blink/internal/fixer/rules/binary_operator_spaces_config_test.go
@@ -22,6 +22,8 @@ func TestBinaryOperatorSpacesConfigCases(t *testing.T) {
 		{"collapse aligned arrow inside attribute", BinaryOperatorSpaces{}, "<?php #[X([\n    'a'   => 1,\n    'bb'  => 2,\n])]\nclass C {}", "<?php #[X([\n    'a' => 1,\n    'bb' => 2,\n])]\nclass C {}"},
 		{"arrow inside attribute string left alone", BinaryOperatorSpaces{}, "<?php #[X('a   => b')]\nclass C {}", "<?php #[X('a   => b')]\nclass C {}"},
 		{"reference assignment is spaced around =", BinaryOperatorSpaces{}, "<?php $a   =&$b;", "<?php $a = &$b;"},
+		{"compound assign follows default without override", BinaryOperatorSpaces{}.WithConfig(map[string]any{"default": "single_space", "operators": map[string]any{"=>": "single_space", "=": "single_space"}}).(fixerRule), "<?php $url .='c'; $a .=$b;", "<?php $url .= 'c'; $a .= $b;"},
+		{"compound assign explicit no_space override", BinaryOperatorSpaces{}.WithConfig(map[string]any{"default": "single_space", "operators": map[string]any{".=": "no_space"}}).(fixerRule), "<?php $url .= 'c';", "<?php $url.='c';"},
 	}
 	for _, c := range cases {
 		got, _ := apply(t, c.rule, c.src)