rector/rules/DeadCode/SideEffect/PureFunctionDetector.php

<?php

declare(strict_types=1);

namespace Rector\DeadCode\SideEffect;

use PhpParser\Node\Expr\FuncCall;
use Rector\NodeNameResolver\NodeNameResolver;

final class PureFunctionDetector
{
    /**
     * @see https://github.com/vimeo/psalm/blob/d470903722cfcbc1cd04744c5491d3e6d13ec3d9/src/Psalm/Internal/Codebase/Functions.php#L288
     * @var string[]
     */
    private const IMPURE_FUNCTIONS = [
        'chdir', 'chgrp', 'chmod', 'chown', 'chroot', 'closedir', 'copy', 'file_put_contents',
        'fopen', 'fread', 'fwrite', 'fclose', 'touch', 'fpassthru', 'fputs', 'fscanf', 'fseek',
        'ftruncate', 'fprintf', 'symlink', 'mkdir', 'unlink', 'rename', 'rmdir', 'popen', 'pclose',
        'fputcsv', 'umask', 'finfo_close', 'readline_add_history', 'stream_set_timeout', 'fflush',

        // stream/socket io
        'stream_context_set_option', 'socket_write', 'stream_set_blocking', 'socket_close',
        'socket_set_option', 'stream_set_write_buffer',

        // meta calls
        'call_user_func', 'call_user_func_array', 'define', 'create_function',

        // http
        'header', 'header_remove', 'http_response_code', 'setcookie',

        // output buffer
        'ob_start', 'ob_end_clean', 'readfile', 'printf', 'var_dump', 'phpinfo',
        'ob_implicit_flush', 'vprintf',

        // mcrypt
        'mcrypt_generic_init', 'mcrypt_generic_deinit', 'mcrypt_module_close',

        // internal optimisation
        'opcache_compile_file', 'clearstatcache',

        // process-related
        'pcntl_signal', 'posix_kill', 'cli_set_process_title', 'pcntl_async_signals', 'proc_close',
        'proc_nice', 'proc_open', 'proc_terminate',

        // curl
        'curl_setopt', 'curl_close', 'curl_multi_add_handle', 'curl_multi_remove_handle',
        'curl_multi_select', 'curl_multi_close', 'curl_setopt_array',

        // apc, apcu
        'apc_store', 'apc_delete', 'apc_clear_cache', 'apc_add', 'apc_inc', 'apc_dec', 'apc_cas',
        'apcu_store', 'apcu_delete', 'apcu_clear_cache', 'apcu_add', 'apcu_inc', 'apcu_dec', 'apcu_cas',

        // gz
        'gzwrite', 'gzrewind', 'gzseek', 'gzclose',

        // newrelic
        'newrelic_start_transaction', 'newrelic_name_transaction', 'newrelic_add_custom_parameter',
        'newrelic_add_custom_tracer', 'newrelic_background_job', 'newrelic_end_transaction',
        'newrelic_set_appname',

        // execution
        'shell_exec', 'exec', 'system', 'passthru', 'pcntl_exec',

        // well-known functions
        'libxml_use_internal_errors', 'libxml_disable_entity_loader', 'curl_exec',
        'mt_srand', 'openssl_pkcs7_sign',
        'mt_rand', 'rand', 'random_int', 'random_bytes',
        'wincache_ucache_delete', 'wincache_ucache_set', 'wincache_ucache_inc',
        'class_alias',

        // php environment
        'ini_set', 'sleep', 'usleep', 'register_shutdown_function',
        'error_reporting', 'register_tick_function', 'unregister_tick_function',
        'set_error_handler', 'user_error', 'trigger_error', 'restore_error_handler',
        'date_default_timezone_set', 'assert_options', 'setlocale',
        'set_exception_handler', 'set_time_limit', 'putenv', 'spl_autoload_register',
        'microtime', 'array_rand',

        // logging
        'openlog', 'syslog', 'error_log', 'define_syslog_variables',

        // session
        'session_id', 'session_name', 'session_set_cookie_params', 'session_set_save_handler',
        'session_regenerate_id', 'mb_internal_encoding', 'session_start',

        // ldap
        'ldap_set_option',

        // iterators
        'rewind', 'iterator_apply',

        // mysqli
        'mysqli_select_db', 'mysqli_dump_debug_info', 'mysqli_kill', 'mysqli_multi_query',
        'mysqli_next_result', 'mysqli_options', 'mysqli_ping', 'mysqli_query', 'mysqli_report',
        'mysqli_rollback', 'mysqli_savepoint', 'mysqli_set_charset', 'mysqli_ssl_set',

        // postgres
        'pg_exec', 'pg_execute', 'pg_connect', 'pg_query_params',

        // ftp
        'ftp_close',

        // bcmath
        'bcscale', 'bcdiv',

        // json
        'json_encode', 'json_decode', 'json_last_error',
    ];

    /**
     * @var NodeNameResolver
     */
    private $nodeNameResolver;

    public function __construct(NodeNameResolver $nodeNameResolver)
    {
        $this->nodeNameResolver = $nodeNameResolver;
    }

    public function detect(FuncCall $funcCall): bool
    {
        return ! $this->nodeNameResolver->isNames($funcCall, self::IMPURE_FUNCTIONS);
    }
}