[9.x] Cast Stringable to string when used with json_encode() (#35680)

* [9.x] Cast Stringable to string when used with json_encode().

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* Update src/Illuminate/Support/Stringable.php

Co-authored-by: Anton Komarev <1849174+antonkomarev@users.noreply.github.com>

* Update Stringable.php

Co-authored-by: Taylor Otwell <taylor@laravel.com>
Co-authored-by: Anton Komarev <1849174+antonkomarev@users.noreply.github.com>

src/Illuminate/Support/Stringable.php

@@ -4,9 +4,10 @@
 
 use Closure;
 use Illuminate\Support\Traits\Macroable;
+use JsonSerializable;
 use Symfony\Component\VarDumper\VarDumper;
 
-class Stringable
+class Stringable implements JsonSerializable
 {
     use Macroable;
 
@@ -722,6 +723,16 @@ public function dd()
         exit(1);
     }
 
+    /**
+     * Convert the object into something JSON serializable.
+     *
+     * @return string
+     */
+    public function jsonSerialize()
+    {
+        return $this->__toString();
+    }
+
     /**
      * Proxy dynamic properties onto methods.
      *

tests/Support/SupportStringableTest.php

@@ -545,4 +545,11 @@ public function testChunk()
         $this->assertInstanceOf(Collection::class, $chunks);
         $this->assertSame(['foo', 'bar', 'baz'], $chunks->all());
     }
+
+    public function testJsonSerializable()
+    {
+        $this->assertSame('"laravel-php-framework"', json_encode($this->stringable('LaravelPhpFramework')->kebab()));
+        $this->assertSame('["laravel-php-framework"]', json_encode([$this->stringable('LaravelPhpFramework')->kebab()]));
+        $this->assertSame('{"title":"laravel-php-framework"}', json_encode(['title' => $this->stringable('LaravelPhpFramework')->kebab()]));
+    }
 }