PHPUnit Test (Lagacy Route, Legacy Container) - test whether user is already created - php

Question

I am using PHP, PHP Legacy Router and PHP Legacy Container.
I am using also PHPUnit test
I am trying to make a correct PHPUnit test, however, I am a begginer and I don`t know whether my code is ok or it is wrong.
In my NewUserService class I write 2 functions to get all emails and if the email is already existed in the db to return an error that user is created already.
My problem is how to test this functionality trough PHPUnit tests in my NewUserServiceTest
This is my functionality to test whether the user is already created
public function getAllUsersEmails()
{
$sql ="SELECT `email` FROM users";
$stmt = $this->container->get('db')->prepare($sql);
$stmt->execute();
if ($stmt->errorCode() != '00000') throw new Exception(sprintf(("Database error (%s): %s"), $stmt->errorCode(), $stmt->errorInfo()[2]));
return $stmt->fetchAll(PDO::FETCH_ASSOC);
}
/**
* #throws Exception
*/
private function repeatingEmailAddress($requestObj){
$allUsersEmails = NewUserService::getAllUsersEmails();
$allUsersEmailsValues = [];
foreach ($allUsersEmails as $value){
$allUsersEmailsValues[]=$value['email'];
}
if(in_array($requestObj['email'], $allUsersEmailsValues)){
throw new Exception("A user with that email is already created.", 400);
}
This is the unit test:
private function repeatingUserEmail(): array
{
$request = $this->createStub(ServerRequestInterface::class);
$requestJsonPayload = '{"email": "mj#hph.io", "role": 2, "first": "Griffin", "last": "Mitchell"}';
$requestStream = fopen('php://memory', 'r+');
fwrite($requestStream, $requestJsonPayload);
rewind($requestStream);
$request->method('getBody')->willReturn(new Stream($requestStream));
$routeArgs = ['id' => 4];
/* <container with user> */
$container = $this->getStandardContainer();
$user = $this->createMock(User::class);
$user->id = '1';
$user->role = '1';
$user->parent_entity = '11';
$user->email='mj#hph.io';
$container->add('current_user', $user);
$response = ['error' => 'A user with that email is already created.'];
$responseJsonPayload = json_encode($response);
$responseStream = fopen('php://memory', 'r+');
fwrite($responseStream, $responseJsonPayload);
rewind($responseStream);
$expectedResponse = $this->createMock(ResponseInterface::class);
$expectedResponse->method('getStatusCode')->willReturn(400);
$expectedResponse->method('getBody')->willReturn(new Stream($responseStream));
return [$request, $routeArgs, $container, $expectedResponse];
}
Is it correct? How should be done in a correct way?

Answer 1

First of all i suggest to make a isEmailExists($email) method that will search this specific email in the database and return bollean response (true/false). So you don't have to pull millions of emails from database and then loop through millions of rows and in the end you just throw an error.
Back to the test. I suggest to use the expectException assertion that you can find in the documentation
You can 1)add one row in you database and then try to pass the same email that will throw this error or 2)partial mock the
isEmailExists($email) to return true and throw your exception (without hit the database at all)