Ignoring 'required' validation rule for inserts.

[nowackipawel]

This is my code:

		$test_model = (new \TestModel);

		CLI::write('INSERT_TEST tes_id + tes_txt' , 'red');
		$test_1 = (new \App\Entities\Test());
		$test_1->tes_id = rand(20,200);
		$test_1->tes_txt = '111' . microtime();
		CLI::write(json_encode($test_1->toRawArray()));
		CLI::write($test_model->save($test_1));
		CLI::write('VALIDATION ERRORS: ' . print_r($test_model->errors(true), true));

		CLI::write('INSERT_TEST tes_id + tes_txt' , 'red');
		$test_2 = (new \App\Entities\Test());
		$test_2->tes_id = rand(20,200);
		$test_2->tes_txt = null;
		CLI::write(json_encode($test_2->toRawArray()));
		CLI::write($test_model->save($test_2));  // PRODUCES INSERT INTO `t_test` (`tes_id`) VALUES (138)

		CLI::write('VALIDATION ERRORS: ' . print_r($test_model->errors(), true)); // NO ERRORS!

and my model has validation rules like:

	protected $validationRules = [
		'tes_txt' 	=> 'required|min_length[2]',
		'tes_json' 	=> 'permit_empty|valid_json'
	];

Results for spark code:

CodeIgniter CLI Tool - Version 4.0.0-alpha.5 - Server-Time: 2019-03-01 08:55:30am

INSERT_TEST tes_id + tes_txt
{"tes_id":139,"tes_txt":"1110.12893900 1551430530","tes_json":null,"tes_created_at":null,"tes_updated_at":null}
139 INSERT INTO `t_test` (`tes_id`, `tes_txt`) VALUES (139, '1110.12893900 1551430530')
VALIDATION ERRORS: 
INSERT_TEST tes_id + tes_txt
{"tes_id":138,"tes_txt":null,"tes_json":null,"tes_created_at":null,"tes_updated_at":null}
138 INSERT INTO `t_test` (`tes_id`) VALUES (138)
VALIDATION ERRORS: 

Unfortunately as long as tes_txt = NULL $test_2 is passing validation. If I change it to '' or 'x' validation is working (required or min_length[2])