[v8.52.0] Invalid JSON was returned from the route.

[kocoten1992]

• Laravel Version: v8.52.0
• PHP Version: PHP 8.0.8
• Database Driver & Version: not relevant

Description:

This code work on v8.51.0, but fail on v8.52.0

Steps To Reproduce:

On any controller:

return response()->json(false);

On testing:

$response = $this->get('/');
  
$response->assertStatus(200);

# v8.51.0
   PASS  Tests\Feature\ExampleTest
  ✓ example

  Tests:  2 passed
  Time:   0.10s

# v8.52.0
   FAIL  Tests\Feature\ExampleTest
  ⨯ example

  ---

  • Tests\Feature\ExampleTest > example
  Invalid JSON was returned from the route.

  at tests/Feature/ExampleTest.php:19
     15▕     public function test_example()
     16▕     {
     17▕         $response = $this->get('/');
     18▕ 
  ➜  19▕         $response->assertStatus(200);
     20▕     }
     21▕ }
     22▕ 

[derekmd]

Laravel currently can't make assertions on response()->json(false)

Your example shows an edge case gap in Illuminate\Testing\TestResponse's ability to make assertions on response()->json(false).

Running the below 3 tests with v8.51.0, the top 2 pass but the last case fails:

public function testResponseJsonNull()
{
    \Illuminate\Support\Facades\Route::get(
        '/json-null',
        fn () => response()->json(null)
    );

    $response = $this->get('/json-null');
    $this->assertSame('{}', $response->content()); // passes
    dump($response->json()); // prints []
    $response->assertStatus(200); // passes
}

public function testResponseJsonTrue()
{
    \Illuminate\Support\Facades\Route::get(
        '/json-true',
        fn () => response()->json(true)
    );

    $response = $this->get('/json-true');
    $this->assertSame('true', $response->content()); // passes
    dump($response->json()); // prints true
    $response->assertStatus(200); // passes
}

public function testResponseJsonFalse()
{
    \Illuminate\Support\Facades\Route::get(
        '/json-false',
        fn () => response()->json(false)
    );

    $response = $this->get('/json-false');
    $this->assertSame('false', $response->content()); // passes
    dump($response->json()); // throws PHPUnit::fail('Invalid JSON was returned from the route.')
    $response->assertStatus(200); // assertion not reached
}

This is caused by the error checking in Illuminate\Testing\TestResponse@decodeResponseJson():

framework/src/Illuminate/Testing/TestResponse.php

Line 851 in 7bd4e6d

if (is_null($decodedResponse) || $decodedResponse === false) {

The $decodedResponse === false expression is checking for Illuminate\Testing\AssertableJsonString's constructor assigning false to property AssertableJsonString@decoded:

framework/src/Illuminate/Testing/AssertableJsonString.php

Lines 39 to 47 in 49ee16b

	if ($jsonable instanceof JsonSerializable) {
	$this->decoded = $jsonable->jsonSerialize();
	} elseif ($jsonable instanceof Jsonable) {
	$this->decoded = json_decode($jsonable->toJson(), true);
	} elseif (is_array($jsonable)) {
	$this->decoded = $jsonable;
	} else {
	$this->decoded = json_decode($jsonable, true);
	}

But in this API response, HTTP response body string false is JSON false that should be transformed to PHP bool value false.

---

v8.52.0 changes causing the exception

The exception is now occurring because v8.52.0 started showing JSON response validation errors in test output on a status code mismatch. Introduced by #38088, a custom PHPUnit feedback message string is computed when asserting the status code integer match like 200 HTTP OK.

So this new code:

framework/src/Illuminate/Testing/TestResponse.php

Lines 194 to 200 in 7bd4e6d

	if ($this->baseResponse->headers->get('Content-Type') === 'application/json') {
	$json = $this->json();
	if (isset($json['errors'])) {
	return $this->statusMessageWithErrors($expected, $actual, $json);
	}
	}

Is now attempting to decode the response body JSON string on status code assertions before any assert*Json() methods are called.

---

Possible framework code fix

A potential fix would be to add a new AssertableJsonString method:

class AssertableJsonString implements ArrayAccess, Countable
{
    // ...

    public function hasInvalidJson()
    {
        return $this->decoded === null || (
            $this->decoded === false && $this->json !== 'false' && ! (
                $this->$json instanceof Jsonable && $jsonable->toJson() === false
            )
        );
    }
}

Then make TestResponse@decodeResponseJson() only throw an exception when that returns true.

I'm not sure why false is being checked since json_decode() returns null upon parse failure. But the decodeResponseJson() method infers that the AssertableJsonString constructor accepting $jsonable value JsonSerializable@jsonSerialize() === false is an error condition.

Edit: Looking at when decodeResponseJson() was added, its false checks seem to be rooted in making assertions on associative array payloads. 5f4a991 You can't make key/value assertions on a false payload. The method was later used by other JSON assertion methods where the false error check doesn't make sense.

[derekmd]

https://github.com/laravel/framework/compare/8.x...derekmd:assert-status-doesnt-fail-on-json-false?expand=1 will at least fix assertStatus() failing.

Before submitting I'll wait on today's #38189 to be merged to avoid Git conflicts.