PhpUnit: The http response is empty though test is carried out fine - php

Question

I am trying to write unit tests for practice on a small application. This is my first time with unit-tests and I have not a very good knowledge. This is what I am trying to do.
$response=$this->request('POST',['crud_controller','add_data' ,$data]);
$this->assertEquals(1,$response);
The function add_data is programmed to return 1 if the data is processed or return -1 otherwise. The data is getting processed but phpUnit shows failed test with
issue:
Failed asserting that null matches expected 1.
I am working in codeigniter and using phpunit for testing.
Complete Test-Case:
<?php
class crud_controller_test extends TestCase{
public function test_add_data(){
$data =array(
'name' => 'badPass',
);
$response=$this->request('POST',['crud_controller','add_data' ,$data]);
$this->assertEquals(1,$response);
//$this->assertEquals(-1,$response);
//$this->assertEquals(0,$response);
}
public function test_update_data(){
$data =array(
'id'=>'29',
'name' => 'badPass',
);
$response=$this->request('POST',['crud_controller','update_data' ,$data]);
var_dump($response);
$this->assertEquals(1,$response);
//$this->assertEquals(-1,$response);
//$this->assertEquals(0,$response);
}
}
?>
Methods getting called:
public function add_data($data){
if($this->crud_model->insert($data) ==true)
return 1;
else
return -1;
//return $this->crud_model->insert($data);
//$this->index();
}
public function update_data($data){
if($this->crud_model->update($data) == true)
return 1;
else
return -1;
//$this->index();
}