<?php
/**
 * PHPCompatibility, an external standard for PHP_CodeSniffer.
 *
 * @package   PHPCompatibility
 * @copyright 2012-2019 PHPCompatibility Contributors
 * @license   https://opensource.org/licenses/LGPL-3.0 LGPL3
 * @link      https://github.com/PHPCompatibility/PHPCompatibility
 */

namespace PHPCompatibility\Sniffs\Lists;

use PHPCompatibility\Sniff;
use PHP_CodeSniffer_File as File;

/**
 * Detect short list syntax for symmetric array destructuring.
 *
 * "The shorthand array syntax (`[]`) may now be used to destructure arrays for
 * assignments (including within `foreach`), as an alternative to the existing
 * `list()` syntax, which is still supported."
 *
 * PHP version 7.1
 *
 * @link https://www.php.net/manual/en/migration71.new-features.php#migration71.new-features.symmetric-array-destructuring
 * @link https://wiki.php.net/rfc/short_list_syntax
 *
 * @since 9.0.0
 */
class NewShortListSniff extends Sniff {


	/**
	 * Returns an array of tokens this test wants to listen for.
	 *
	 * @since 9.0.0
	 *
	 * @return array
	 */
	public function register() {
		return array( \T_OPEN_SHORT_ARRAY );
	}

	/**
	 * Processes this test, when one of its tokens is encountered.
	 *
	 * @since 9.0.0
	 *
	 * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned.
	 * @param int                   $stackPtr  The position of the current token in the
	 *                                         stack passed in $tokens.
	 *
	 * @return int|void Integer stack pointer to skip forward or void to continue
	 *                  normal file processing.
	 */
	public function process( File $phpcsFile, $stackPtr ) {
		if ( $this->supportsBelow( '7.0' ) === false ) {
			return;
		}

		if ( $this->isShortList( $phpcsFile, $stackPtr ) === false ) {
			return;
		}

		$tokens = $phpcsFile->getTokens();
		$closer = $tokens[ $stackPtr ]['bracket_closer'];

		$hasVariable = $phpcsFile->findNext( \T_VARIABLE, ( $stackPtr + 1 ), $closer );
		if ( $hasVariable === false ) {
			// List syntax is only valid if there are variables in it.
			return;
		}

		$phpcsFile->addError(
			'The shorthand list syntax "[]" to destructure arrays is not available in PHP 7.0 or earlier.',
			$stackPtr,
			'Found'
		);

		return ( $closer + 1 );
	}
}
