[5.4] Don't call method cleanParameterBag() twice for json request

[dmasior]

Fix for bug I found in TransformsRequest middleware. Currently for json request it is calling method cleanParameterBag 2x so method transform() is executed 2x. The result is malformed data (transformed twice).

[taylorotwell]

How do I recreate the bug on a fresh Laravel installation?

[dmasior]

To reproduce error I created test:

<?php

namespace Tests\Feature;

use Tests\TestCase;

class ExampleTest extends TestCase
{
    /**
     * @return void
     */
    public function testBasicTest()
    {
        $response = $this->postJson('/', ['test' => 2]);

        $response->assertJson(['test' => 8,]); // Expected to be 2+2=4 not 8 (2+2+4) as IncrementVarTwice->transform() method should be executed once
    }
}

then defined example route:

\Route::post('/', function (Request $request) {
    return \Response::json($request->all());
});

and a middleware:

<?php

namespace App\Http\Middleware;

use Illuminate\Foundation\Http\Middleware\TransformsRequest;

class IncrementVarTwice extends TransformsRequest
{
    protected function transform($key, $value)
    {
        if ($key === 'test') {
            $value = $value + $value;
        }

        return $value;
    }
}

and registered it in App\Http\Kernel:

protected $middleware = [
        \App\Http\Middleware\IncrementVarTwice::class,
    ];

After that all i got:

PHPUnit 5.7.19 by Sebastian Bergmann and contributors.

..                                                                  2 / 2 (100%)

Time: 96 ms, Memory: 6.00MB

OK (2 tests, 2 assertions)

Which is NOK

[dmasior]

The problem occurs only when sending data in json request. Not as query param, because $request->query is transformed only once:

    /**
     * Clean the request's data.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return void
     */
    protected function clean($request)
    {
        $this->cleanParameterBag($request->query);

        $this->cleanParameterBag($request->request);

        if ($request->isJson()) {
            $this->cleanParameterBag($request->json());
        }
    }