Make PropertyHook::getStmts() less incorrect

Still missing the assignment to the correct property, but at
least we're not returning from a non-void function now...

lib/PhpParser/Node/PropertyHook.php

@@ -3,6 +3,7 @@
 namespace PhpParser\Node;
 
 use PhpParser\Modifiers;
+use PhpParser\Node\Stmt\Expression;
 use PhpParser\Node\Stmt\Return_;
 use PhpParser\NodeAbstract;
 
@@ -68,7 +69,15 @@ public function isFinal(): bool {
 
     public function getStmts(): ?array {
         if ($this->body instanceof Expr) {
-            return [new Return_($this->body)];
+            $name = $this->name->toLowerString();
+            if ($name === 'get') {
+                return [new Return_($this->body)];
+            }
+            if ($name === 'set') {
+                // TODO: This should generate $this->prop = $expr, but we don't know the property name.
+                return [new Expression($this->body)];
+            }
+            throw new \LogicException('Unknown property hook "' . $name . '"');
         }
         return $this->body;
     }

test/PhpParser/Node/PropertyHookTest.php

@@ -3,6 +3,9 @@
 namespace PhpParser\Node;
 
 use PhpParser\Modifiers;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\Stmt\Expression;
+use PhpParser\Node\Stmt\Return_;
 
 class PropertyHookTest extends \PHPUnit\Framework\TestCase {
     /**
@@ -31,4 +34,24 @@ public static function provideModifiers() {
             ['final'],
         ];
     }
+
+    public function testGetStmts(): void {
+        $expr = new Variable('test');
+        $get = new PropertyHook('get', $expr);
+        $this->assertEquals([new Return_($expr)], $get->getStmts());
+
+        // TODO: This is incorrect.
+        $set = new PropertyHook('set', $expr);
+        $this->assertEquals([new Expression($expr)], $set->getStmts());
+    }
+
+    public function testSetStmtsUnknownHook(): void
+    {
+        $expr = new Variable('test');
+        $get = new PropertyHook('foobar', $expr);
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Unknown property hook "foobar"');
+        $get->getStmts();
+    }
 }