Sends error to Slack via Webhook

error_handler_slack.php

<?php

// Set your Slack WEBHOOK here
define('_SLACK_ERRORS_CHANNEL_WEBHOOK_URL', '<WEBHOOK>');

// Register function that will be executed in the end of PHP runtime
register_shutdown_function("shutdown_error_handler");

/*
 * Sends a message to channel on Slack, example:
 *
 *
    Error (E_ERROR) | PHP Stopped

    File (/PATH/TO/FILE:LINE)

    Message (Uncaught Exception: Error Handler(\Error) not foundError Object
    (
       ...error details...
    )
 *
 * In order to make it work, just define a constant somewhere like:
 * define('_SLACK_ERRORS_CHANNEL_WEBHOOK_URL', '<WEBHOOK>');
 *
 * ...where <WEBHOOK> is the webhook you received from Slack
 *
 * */
function shutdown_error_handler()
{
    $slackWebhookUrlIsDefined = defined('_SLACK_ERRORS_CHANNEL_WEBHOOK_URL');
    if (!$slackWebhookUrlIsDefined) return;
    $slackWebhookUrl = _SLACK_ERRORS_CHANNEL_WEBHOOK_URL;
    
    $lasterror = error_get_last();

    $type = $lasterror['type'];
    $typeName = FriendlyErrorType($type);
    $message = $lasterror['message'];
    $file = $lasterror['file'];
    $line = $lasterror['line'];

    // Choose which errors you want to be sent to Slack
    // If your code generates too many Warnings, you can
    // comment them out from the array
    if(isset($lasterror) && in_array($typeName, [
        'E_WARNING', 'E_CORE_WARNING', 'E_USER_WARNING',
        'E_ERROR', 'E_COMPILE_ERROR', 'E_USER_ERROR',
        'E_PARSE',
        ]))
    {
        //Figure out whether we are using http or https.
        $http = 'http';
        //If HTTPS is present in our $_SERVER array, the URL should
        //start with https:// instead of http://
        if(isset($_SERVER['HTTPS'])){
            $http = 'https';
        }
        //Get the HTTP_HOST.
        $host = $_SERVER['HTTP_HOST'];
        //Get the REQUEST_URI. i.e. The Uniform Resource Identifier.
        $requestUri = $_SERVER['REQUEST_URI'];
        //Finally, construct the full URL.
        //Use the function htmlentities to prevent XSS attacks.
        $full_url = $http . '://' . htmlentities($host) . htmlentities($requestUri);

        $payload = [
          'text' => "
*{$typeName}* occured in \n
`{$file}` on line `{$line}` \n
On URL: {$full_url} \n
Here is what I know about it: \n
```{$message}```",
        ];
        $ch = curl_init($slackWebhookUrl);
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array(
            'Content-Type: application/json',
        ));
        $result = curl_exec($ch);
        curl_close($ch);

        if($result === false)
        {
            die('Curl error: ' . curl_error($ch));
        }
    }
}