Error logging during Git Updater webhook

error-logging.php

<?php
/**
 * Error logging.
 *
 * To log different sets of hooks the following constant
 * ERROR_LOGGING_HOOKS will need to be set.
 *
 * ERROR_LOGGING_HOOKS accepts an array of any combination of the following elements.
 *  ( 'upgrade_hooks' AND/OR 'filesystem_hooks' )
 * eg, `define( 'ERROR_LOGGING_HOOKS', [ 'filesystem_hooks' ] );`
 *
 * @package Fragen\Error_Logging
 *
 * Plugin Name:       Error Logging
 * Plugin URI:        https://gist.github.com/afragen/a09b52047bf1d7f11b622941678824cc
 * Description:       Error logging to debug.log of WP_Error and during specific sets of filter hooks.
 * Version:           1.0.0
 * Author:            Andy Fragen
 * License:           MIT
 * Requires at least: 5.9
 * Requires PHP:      7.4
 * Gist Plugin URI:   https://gist.github.com/afragen/a09b52047bf1d7f11b622941678824cc
 */

namespace Fragen;

/**
 * Class Error_Logging.
 */
class Error_Logging {
	/** @var array */
	private $hooks;

	/**
	 * Constructor.
	 *
	 * @param array $hooks Array of hooks to process.
	 */
	public function __construct( $hooks ) {
		$this->hooks = $hooks;
	}

	/**
	 * Sets hooks to log data.
	 *
	 * @return void
	 */
	public function init() {
		foreach ( $this->hooks as $hook => $args ) {
			add_filter( $hook, array( $this, 'log_filter' ), $args['priority'], $args['accepted_args'] );
		}
	}

	/**
	 * Log hook data to debug.log.
	 *
	 * @param array ...$args Hook args.
	 *
	 * @return mixed
	 */
	public static function log_filter( ...$args ) {
		$hook = current_filter();

		error_log( var_export( $hook, true ) );
		foreach ( $args as $arg ) {
			$arg = is_object( $arg ) ? serialize( $arg ) : $arg;
			error_log( var_export( $arg, true ) );
		}
		error_log( "\r\n" );

		return self::is_action( $hook ) ? null : $args[0];
	}

	/**
	 * Return value of 'doing_action' for hook.
	 *
	 * @global array $wp_filters Array of called hooks.
	 * @param string $filter     Name of hook.
	 *
	 * @return bool
	 */
	private static function is_action( $hook ) {
		global $wp_filter;

		$object     = $wp_filter[ $hook ];
		$reflection = new \ReflectionClass( $object );
		$property   = $reflection->getProperty( 'doing_action' );
		$property->setAccessible( true );

		return $property->getValue( $object );
	}
}

$hook_sets = array(
	'wp_error'         => array(
		'wp_error_added' => array(
			'priority'      => 10,
			'accepted_args' => 4,
		),
	),
	'filesystem_hooks' => array(
		'filesystem_method' => array(
			'priority'      => 10,
			'accepted_args' => 4,
		),
	),
	'upgrade_hooks'    => array(
		'upgrader_package_options'        => array(
			'priority'      => 10,
			'accepted_args' => 1,
		),
		'upgrader_pre_download'           => array(
			'priority'      => 10,
			'accepted_args' => 4,
		),
		'upgrader_pre_install'            => array(
			'priority'      => 10,
			'accepted_args' => 2,
		),
		'upgrader_source_selection'       => array(
			'priority'      => 10,
			'accepted_args' => 4,
		),
		'upgrader_clear_destination'      => array(
			'priority'      => 10,
			'accepted_args' => 4,
		),
		'upgrader_post_install'           => array(
			'priority'      => 10,
			'accepted_args' => 3,
		),
		'upgrader_install_package_result' => array(
			'priority'      => 10,
			'accepted_args' => 3,
		),
		'unzip_file_use_ziparchive'       => array(
			'priority'      => 10,
			'accepted_args' => 1,
		),
		'pre_unzip_file'                  => array(
			'priority'      => 10,
			'accepted_args' => 5,
		),
		'unzip_file'                      => array(
			'priority'      => 10,
			'accepted_args' => 1,
		),
	),
);

/*
 * To log different sets of hooks the following constant
 * ERROR_LOGGING_HOOKS will need to be set.
 *
 * ERROR_LOGGING_HOOKS accepts an array of any combination of the following elements.
 *  ( 'upgrade_hooks' AND/OR 'filesystem_hooks' )
 * eg, `define( 'ERROR_LOGGING_HOOKS', [ 'filesystem_hooks' ] );`
 */
$hooks = $hook_sets['wp_error'];
if ( defined( 'ERROR_LOGGING_HOOKS' ) ) {
	foreach ( ERROR_LOGGING_HOOKS as $set ) {
		if ( isset( $hook_sets[ $set ] ) ) {
			foreach ( $hook_sets[ $set ] as $hook => $args ) {
				$hooks[ $hook ] = $args;
			}
		}
	}
}

( new Error_Logging( $hooks ) )->init();