[3.9] Fix/stringable sort

src/Query/Builder.php

@@ -512,7 +512,7 @@ public function orderBy($column, $direction = 'asc')
         if ($column == 'natural') {
             $this->orders['$natural'] = $direction;
         } else {
-            $this->orders[$column] = $direction;
+            $this->orders[(string) $column] = $direction;
         }
 
         return $this;

tests/QueryTest.php

@@ -239,6 +239,17 @@ public function testOrder(): void
         $this->assertEquals(35, $user->age);
     }
 
+    public function testStringableOrder(): void
+    {
+        $age = new stringableObject('age');
+
+        $user = User::whereNotNull('age')->orderBy($age, 'asc')->first();
+        $this->assertEquals(13, $user->age);
+
+        $user = User::whereNotNull('age')->orderBy($age, 'desc')->first();
+        $this->assertEquals(37, $user->age);
+    }
+
     public function testGroupBy(): void
     {
         $users = User::groupBy('title')->get();
@@ -470,3 +481,20 @@ public function testMultipleSortOrder(): void
         $this->assertEquals('Brett Boe', $subset[2]->name);
     }
 }
+
+/**
+ * Mockup class to test stringable objects.
+ */
+class stringableObject implements Stringable {
+    private string $string;
+
+    public function __construct(string $string)
+    {
+        $this->string = $string;
+    }
+
+    public function __toString()
+    {
+        return $this->string;
+    }
+}