fix: API\ResponseTrait can't return string as JSON

[kenjis]

Description
Fixes #8397

• When you pass a string, $this->respond() returns text/html. But it should return application/json.
  • When you pass an int, $this->respond() returns application/json.
  • When you pass a boolean, $this->respond() returns application/json.

Before:

$ curl -v http://localhost:8080/
...
< HTTP/1.1 200 OK
< Host: localhost:8080
< Date: Wed, 31 Jan 2024 07:57:40 GMT
< Connection: close
< X-Powered-By: PHP/8.2.15
< Cache-Control: no-store, max-age=0, no-cache
< Content-Type: text/html; charset=UTF-8
< 
* Closing connection
message

After:

$ curl -v http://localhost:8080/
...
< HTTP/1.1 200 OK
< Host: localhost:8080
< Date: Wed, 31 Jan 2024 07:59:11 GMT
< Connection: close
< X-Powered-By: PHP/8.2.15
< Cache-Control: no-store, max-age=0, no-cache
< Content-Type: application/json; charset=UTF-8
< 
* Closing connection
"message"

<?php

namespace App\Controllers;

use CodeIgniter\API\ResponseTrait;

class Home extends BaseController
{
    use ResponseTrait;

    public function index()
    {
        return $this->respond('message', 200);
    }
}

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[michalsn]

Unless we will be able to parse the same JSON on the input, I think I will not be in favor.

IMO we should support the same JSON parsing options for both: Request and Response.

[kenjis]

We can parse the string JSON "message".

$routes->post('/', 'Home::index');

<?php

namespace App\Controllers;

class Home extends BaseController
{
    public function index(): string
    {
        $json = $this->request->getJSON();
        echo $json; exit;
    }
}

$ curl -H 'Content-Type: application/json' -d '"message"' localhost:8080/
message

[michalsn]

Sorry, looks like I was mistaken. I thought we had a problem with that.

[trampgeek]

Looks good to me. Many thanks, Kenjis.

[kenjis]

Added changelog and upgrade guide.