fix(parser): optimize concat assignment and ternary expression handling

- Simplified concat assignment logic by checking for Concat instance directly instead of flattening
- Changed SelectionExpressionTrait to use parseExprAsValue for ternary branches
- Added proper handling of void branch conversion to null in ternary expressions
- Added tests for concat assignment to inherited properties
- Added tests for ternary expressions with void branches and side effects

src/Parser/AssignOpTrait.php

@@ -583,9 +583,7 @@ trait AssignOpTrait
         }
 
         if ($this->isAssignOpConcat($op)) {
-            $items = [];
+            if (!($node->expr instanceof Expr\BinaryOp\Concat)) {
-            $this->flattenConcatExpr($node->expr, $items);
-            if (count($items) === 1) {
                 return $var . '.append(' . $this->parseExprAsValue($node->expr) . ')';
             }
             return $var . ' = php::toString(' . $this->parseFlattenedConcat($node->expr, [$var]) . ')';

src/Parser/SelectionExpressionTrait.php

@@ -25,7 +25,7 @@ trait SelectionExpressionTrait
         [$cond, $condBeforeStmts, $condAfterStmts] = $this->parseExprWithCapturedStmts($expr->cond);
         $ifBeforeStmtCount = count($this->context->beforeStmtLines);
         $ifAfterStmtCount = count($this->context->afterStmtLines);
-        $if = $this->parseExpr($expr->if);
+        $if = $this->parseExprAsValue($expr->if);
         $ifBeforeStmts = array_slice($this->context->beforeStmtLines, $ifBeforeStmtCount);
         $ifAfterStmts = array_slice($this->context->afterStmtLines, $ifAfterStmtCount);
         $this->context->beforeStmtLines = array_slice($this->context->beforeStmtLines, 0, $ifBeforeStmtCount);
@@ -33,7 +33,7 @@ trait SelectionExpressionTrait
 
         $elseBeforeStmtCount = count($this->context->beforeStmtLines);
         $elseAfterStmtCount = count($this->context->afterStmtLines);
-        $else = $this->parseExpr($expr->else);
+        $else = $this->parseExprAsValue($expr->else);
         $elseBeforeStmts = array_slice($this->context->beforeStmtLines, $elseBeforeStmtCount);
         $elseAfterStmts = array_slice($this->context->afterStmtLines, $elseAfterStmtCount);
         $this->context->beforeStmtLines = array_slice($this->context->beforeStmtLines, 0, $elseBeforeStmtCount);
@@ -206,4 +206,3 @@ trait SelectionExpressionTrait
     }
 
 }
-

tests/compiler/operator/concat-assign-inherited-property.phpt

@@ -0,0 +1,29 @@
+--TEST--
+concat assignment to an inherited property preserves value and reference arguments
+--FILE--
+<?php
+
+class QueryConnection
+{
+    protected $query = '';
+}
+
+class MongoConnection extends QueryConnection
+{
+    public function build(): string
+    {
+        $this->query .= '.sort(' . json_encode(['id' => 1]) . ')';
+        $this->query .= '.skip(' . 2 . ')';
+        $this->query .= ';';
+        return $this->query;
+    }
+}
+
+function main(): void
+{
+    $connection = new MongoConnection();
+    var_dump($connection->build());
+}
+?>
+--EXPECT--
+string(24) ".sort({"id":1}).skip(2);"

tests/compiler/operator/ternary-void-branches.phpt

@@ -0,0 +1,48 @@
+--TEST--
+ternary expressions convert void branches to null after their side effects
+--FILE--
+<?php
+
+class OptimisticLock
+{
+    private int $calls = 0;
+
+    public function check(bool $exists)
+    {
+        return $exists
+            ? $this->updateLockVersion()
+            : $this->recordLockVersion();
+    }
+
+    public function calls(): int
+    {
+        return $this->calls;
+    }
+
+    private function updateLockVersion(): void
+    {
+        echo "update\n";
+        $this->calls++;
+    }
+
+    private function recordLockVersion(): void
+    {
+        echo "record\n";
+        $this->calls++;
+    }
+}
+
+function main(): void
+{
+    $lock = new OptimisticLock();
+    var_dump($lock->check(true));
+    var_dump($lock->check(false));
+    var_dump($lock->calls());
+}
+?>
+--EXPECT--
+update
+NULL
+record
+NULL
+int(2)