Implement support for partial unpacking

Author: thekid

src/main/php/lang/ast/emit/RewriteCloneWith.class.php

@@ -12,7 +12,8 @@ protected function emitClone($result, $clone) {
     // Wrap clone with, e.g. clone($x, ['id' => 6100]), inside an IIFE which
     /// iterates over the property-value pairs, assigning them to the clone.
     if ($with) {
-      $result->out->write('(function($c, array $a) { foreach ($a as $p=>$v) { $c->$p= $v; } return $c;})(clone ');
+      $result->out->write('(function($object, array $withProperties) {');
+      $result->out->write('foreach ($withProperties as $p=>$v) { $object->$p=$v; } return $object;})(clone ');
       $this->emitOne($result, $expr);
       $result->out->write(',');
       $this->emitOne($result, $with);
@@ -22,7 +23,7 @@ protected function emitClone($result, $clone) {
       $this->emitOne($result, $expr);
     } else if ($expr instanceof UnpackExpression) {
       $result->out->write('(function($u) { $c= clone $u["object"] ?? $u[0];');
-      $result->out->write('foreach ($u["withProperties"] ?? $u[1] ?? [] as $p=>$v) { $c->$p= $v; } return $c;})(');
+      $result->out->write('foreach ($u["withProperties"] ?? $u[1] ?? [] as $p=>$v) { $c->$p=$v; } return $c;})(');
       $this->emitOne($result, $expr->expression);
       $result->out->write(')');
     } else {

src/test/php/lang/ast/unittest/emit/CloningTest.class.php

@@ -90,12 +90,33 @@ public function run($in) { return '.$expression.'; }
   public function clone_unpack() {
     $clone= $this->run('class %T {
       public function run($in) {
-        $args= ["object" => $in];
-        return clone(...$args);
+        return clone(...["object" => $in]);
       }
     }', $this->fixture);
 
-    Assert::true($clone instanceof $this->fixture && $this->fixture !== $clone);
+    Assert::equals('<id: 2, name: Test>', $clone->toString());
+  }
+
+  #[Test]
+  public function clone_unpack_with_properties() {
+    $clone= $this->run('class %T {
+      public function run($in) {
+        return clone(...["object" => $in, "withProperties" => ["name" => "Changed"]]);
+      }
+    }', $this->fixture);
+
+    Assert::equals('<id: 2, name: Changed>', $clone->toString());
+  }
+
+  #[Test]
+  public function clone_unpack_only_properties() {
+    $clone= $this->run('class %T {
+      public function run($in) {
+        return clone($in, ...["withProperties" => ["name" => "Changed"]]);
+      }
+    }', $this->fixture);
+
+    Assert::equals('<id: 2, name: Changed>', $clone->toString());
   }
 
   #[Test]