PHPunit: can't assert API login test - phpunit

Question

I'm trying to follow best practices using TDD to build the auth logic with Sanctum. But haven't been able to pass the login test.
Using postman the route works well:
But the test is not behaving as expected. It'd simply fail.
1) Tests\Feature\LoginTest::test_login_route_api
Expected status code 200 but received 401.
Failed asserting that 200 is identical to 401.
I tried to pass a token as header or body and it has not helped.
The test
public function test_login_route_api()
{
$this->withoutExceptionHandling();
//using RefreshDatabase
$user = User::factory()->create();
$response = $this->post('/api/login', [
'email' => $user->email,
'password' => $user->password,
], []);
$response->dumpHeaders();
$response->dumpSession();
$response->dump();
$response->assertStatus(200);
LoginController (method as advised in Laravel Documentation https://laravel.com/docs/8.x/authentication#authenticating-users):
public function login(Request $request)
{
$credentials = $request->only('email', 'password');
if (Auth::attempt($credentials)) {
// $request->session()->regenerate();
$user = Auth::user();
// $success['token'] = $user->createToken('MyApp')->plainTextToken;
$success['token'] = $request->token;
$success['name'] = $user->name;
return response([$success, 'logged in'], 200);
}
return response('fail!', 401);
}
The route:
Route::name('api')->group(function () {
Route::post('/login', [LoginController::class, 'login']);
// some routes
});
phpunit.xml uncommented
<server name="DB_CONNECTION" value="sqlite"/>
<server name="DB_DATABASE" value=":memory:"/>
Not sure what's going on, I've read some similar topics but none has helped me.
Thank you,

Answer 1

Ok, solved it.
Somehow, using factory()->make() or factory()->create() with RefreshDatabase wasn't accepting the $user as valid $credentials.
I had to use an user from with a seeded database like so: $user = User::first();
This would make the test pass.
Any idea why factory users are not passing the test?