I’m trying to get a mock of current user.

$user = DrupaluserEntityUser::load(Drupal::currentUser()->id());

For this, I extend UnitTestCase class and load the User class methods.

$methods = get_class_methods('DrupaluserEntityUser');

Since load() is a User class method, I have created a mock of the User class, disabled its constructor, and set all methods of this class, including load() which is the method I actually need.

$user = $this->getMockBuilder('DrupaluserEntityUser')
  ->disableOriginalConstructor()
  ->setMethods($methods)
  ->getMock();

Since the method is set now, I’m trying to call this method once and not sure what it will return exactly.

$user->expects($this->once())
  ->method('load')
  ->will($this->returnValue('admin'));

Now, while running this test, I got an error.

SymfonyComponentDependencyInjectionExceptionServiceNotFoundException:
You have requested a non-existent service "entity.manager".

What’s the need of injecting the entity.manager service?

Although load() is a method of the entity storage interface, it also exists in the User class.
Why does this error come up?

Can I load the current user without mocking the entity.manager class?

The actual method for which I’m doing unit testing is the following.

public static function get_ctype_field_value($field) {
  $user = user_load(Drupal::currentUser()->id());
  $ulm = get_type_id($user); 
  $local_market = DrupalnodeEntityNode::load($ulm);
  $llf = '';
  if ($local_market) {
    // Get the field value from the LM.
    if ($local_market->hasField($field)) {
      $localmarket_field = $local_market->$field->value;
    }
  }
  return $localmarket_field;
}