What's the right way to add a custom Helper method for unit test suite in Codeception?

Question

I am trying to add a custom helper method to unit test suite, but when running the test I get Fatal error: Uncaught ArgumentCountError: Too few arguments to function error.

This is what I have so far

1. Adding the method to _support/Helper/Unit.php
2. Running the build command
3. Setup actor in suite.yml
4. Calling the method via the actor
5. Running test

When I run the test I get:

ArgumentCountError: Too few arguments to function ExampleTest::__construct(), 0

_support/Helper/Unit.php:

namespace Helper;

// here you can define custom actions
// all public methods declared in helper class will be available in $I

class Unit extends \Codeception\Module
{
  public function get_hello()
  {
    return 'Hello';
  }
}

Test method:

public function testMe1(\UnitTester $I)
{
  $hello = $I->get_hello();
  $this->assertEquals(2, $hello);
}

# Codeception Test Suite Configuration

#

# Suite for unit (internal) tests.

class_name: UnitTester
modules:
  enabled:
    - Asserts
    - \Helper\Unit

Why doesn't testme1() accept any arguments? What step am I missing?

Answer 1

Unit tests methods don't get actor passed as a parameter.

You can call them on $this->tester, like in this example

function testSavingUser()
{
    $user = new User();
    $user->setName('Miles');
    $user->setSurname('Davis');
    $user->save();
    $this->assertEquals('Miles Davis', $user->getFullName());

    $this->tester->seeInDatabase('users', ['name' => 'Miles', 'surname' => 'Davis']);
}