Sample phpunit test

simple.php

<?php
// set up the mock
class testUser extends PHPUnit_Test_Case {
  
  public function testUserCreate()
  {
    $user = Mockery::mock('models_user');
    $user->shouldReceive('select')
         ->once()
         ->with($id)
         ->andReturn($user);
    $user->shouldReceive('isLoader')
         ->once()
         ->andReturn(false);
    $user->shouldReceive('create')
         ->with($id, $username, $password)
         ->once()
         ->andReturn(true);
    
    // initiate your controller
    $controller = new Controllers_Users($user); // your inject the mock instead of the real user model
    $_post['user'] = 'userinfo';    // set up the 
    $_server['http_verb'] = 'POST'; // fake php post verb
    $response = $controller->create_user() // what ever the way you would inact the action
    
    $this->assertEquals(['status' => 1], $response->toJson()); // or what ever
  }
}