Can't create a Laravel Passport token in feature test - php

Question

Since upgrading my application from Laravel 7 to 8, I've been having some minor issues with Laravel Passport. I created a test feature to retrieve a Passport token to make sure it was working, but I can't get it back. When I call passport.token I always get the same message:
array:3 [
"error" => "invalid_client"
"error_description" => "Client authentication failed"
"message" => "Client authentication failed"
]
I have tried several things, but here is my current code:
use Illuminate\Support\Str;
use Laravel\Passport\Client as OauthClient;
use Modules\Sapiendo\Tests\SapiendoTestCase;
/** #test */
public function we_can_authenticate_and_use_api_endpoints_with_client_credential_grant_token()
{
$customer = $this->createFullCustomer();
/** #var OauthClient $oauthClient */
$oauthClient = OauthClient::create([
'user_id' => null,
'name' => 'ClientCredentials Grant Client',
'secret' => Str::random(40),
'redirect' => 'http://localhost',
'personal_access_client' => false,
'password_client' => false,
'revoked' => false,
]);
$state = Str::random(40);
$autorization = $this->get(route('passport.authorizations.authorize', [
'client_id' => $oauthClient->id,
'redirect_uri' => 'http://localhost',
'response_type' => 'code',
'scope' => '',
'state' => $state,
]));
$autorization->assertStatus(302);
// D'abord on demande un token avec les identifiants créés
$tokenRequest = $this->post(route('passport.token'), [
'grant_type' => 'client_credentials',
'client_id' => $oauthClient->getKey(),
'client_secret' => $oauthClient->secret,
'code' => $state,
]);
//->assertSuccessful();
dd($tokenRequest->json());
...
Before this update I didn't have to go through the passport.authorizations.authorize route to get the code, I could go directly to the passport.token step

Answer 1

Since Passport 9.0, the client ID and secret are hashed. There is a function to retrieve this non-hashed secret from the Passport client object
$oauthClient = OauthClient::create([
'user_id' => null,
'name' => 'ClientCredentials Grant Client',
'secret' => Str::random(40),
'redirect' => 'http://localhost',
'personal_access_client' => false,
'password_client' => false,
'revoked' => false,
]);
$tokenRequest = $this->post(route('passport.token'), [
'grant_type' => 'client_credentials',
'client_id' => $oauthClient->id,
'client_secret' => $oauthClient->getPlainSecretAttribute(),
'code' => $state,
]);