src/utils/asset/src/JSMin.php
<?php
/**
* Part of the Antares package.
*
* NOTICE OF LICENSE
*
* Licensed under the 3-clause BSD License.
*
* This source file is subject to the 3-clause BSD License that is
* bundled with this package in the LICENSE file.
*
* @package Antares Core
* @version 0.9.0
* @author Antares Team
* @license BSD License (3-clause)
* @copyright (c) 2017, Antares
* @link http://antaresproject.io
*/
namespace Antares\Asset;
/**
* JSMin.php - modified PHP implementation of Douglas Crockford's JSMin.
*
* <code>
* $minifiedJs = JSMin::minify($js);
* </code>
*
* This is a modified port of jsmin.c. Improvements:
*
* Does not choke on some regexp literals containing quote characters. E.g. /'/
*
* Spaces are preserved after some add/sub operators, so they are not mistakenly
* converted to post-inc/dec. E.g. a + ++b -> a+ ++b
*
* Preserves multi-line comments that begin with /*!
*
* PHP 5 or higher is required.
*
* Permission is hereby granted to use this version of the library under the
* same terms as jsmin.c, which has the following license:
*
* --
* Copyright (c) 2002 Douglas Crockford (www.crockford.com)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is furnished to do
* so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* The Software shall be used for Good, not Evil.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
* --
*
* @package JSMin
* @author Ryan Grove <ryan@wonko.com> (PHP port)
* @author Steve Clay <steve@mrclay.org> (modifications + cleanup)
* @author Andrea Giammarchi <http://www.3site.eu> (spaceBeforeRegExp)
* @copyright 2002 Douglas Crockford <douglas@crockford.com> (jsmin.c)
* @copyright 2008 Ryan Grove <ryan@wonko.com> (PHP port)
* @license http://opensource.org/licenses/mit-license.php MIT License
* @link http://code.google.com/p/jsmin-php/
*/
use Exception;
class JSMin
{
const ORD_LF = 10;
const ORD_SPACE = 32;
const ACTION_KEEP_A = 1;
const ACTION_DELETE_A = 2;
const ACTION_DELETE_A_B = 3;
protected $a = "\n";
protected $b = '';
protected $input = '';
protected $inputIndex = 0;
protected $inputLength = 0;
protected $lookAhead = null;
protected $output = '';
protected $lastByteOut = '';
protected $keptComment = '';
/**
* Minify Javascript.
*
* @param string $js Javascript to be minified
*
* @return string
*/
public static function minify($js)
{
$jsmin = new JSMin($js);
return $jsmin->min();
}
/**
* @param string $input
*/
public function __construct($input)
{
$this->input = $input;
}
/**
* Perform minification, return result
*
* @return string
*/
public function min()
{
if ($this->output !== '') { // min already run
return $this->output;
}
$mbIntEnc = null;
if (function_exists('mb_strlen') && ((int) ini_get('mbstring.func_overload') & 2)) {
$mbIntEnc = mb_internal_encoding();
mb_internal_encoding('8bit');
}
if (isset($this->input[0]) && $this->input[0] === "\xef") {
$this->input = substr($this->input, 3);
}
$this->input = str_replace("\r\n", "\n", $this->input);
$this->inputLength = strlen($this->input);
$this->action(self::ACTION_DELETE_A_B);
while ($this->a !== null) {
// determine next command
$command = self::ACTION_KEEP_A; // default
if ($this->a === ' ') {
if (($this->lastByteOut === '+' || $this->lastByteOut === '-') && ($this->b === $this->lastByteOut)) {
// Don't delete this space. If we do, the addition/subtraction
// could be parsed as a post-increment
} elseif (!$this->isAlphaNum($this->b)) {
$command = self::ACTION_DELETE_A;
}
} elseif ($this->a === "\n") {
if ($this->b === ' ') {
$command = self::ACTION_DELETE_A_B;
// in case of mbstring.func_overload & 2, must check for null b,
// otherwise mb_strpos will give WARNING
} elseif ($this->b === null || (false === strpos('{[(+-!~', $this->b) && !$this->isAlphaNum($this->b))) {
$command = self::ACTION_DELETE_A;
}
} elseif (!$this->isAlphaNum($this->a)) {
if ($this->b === ' ' || ($this->b === "\n" && (false === strpos('}])+-"\'', $this->a)))) {
$command = self::ACTION_DELETE_A_B;
}
}
$this->action($command);
}
$this->output = trim($this->output);
if ($mbIntEnc !== null) {
mb_internal_encoding($mbIntEnc);
}
return $this->output;
}
/**
* ACTION_KEEP_A = Output A. Copy B to A. Get the next B.
* ACTION_DELETE_A = Copy B to A. Get the next B.
* ACTION_DELETE_A_B = Get the next B.
*
* @param int $command
* @throws JSMin_UnterminatedRegExpException|JSMin_UnterminatedStringException
*/
protected function action($command)
{
// make sure we don't compress "a + ++b" to "a+++b", etc.
if ($command === self::ACTION_DELETE_A_B && $this->b === ' ' && ($this->a === '+' || $this->a === '-')) {
// Note: we're at an addition/substraction operator; the inputIndex
// will certainly be a valid index
if ($this->input[$this->inputIndex] === $this->a) {
// This is "+ +" or "- -". Don't delete the space.
$command = self::ACTION_KEEP_A;
}
}
switch ($command) {
case self::ACTION_KEEP_A: // 1
$this->output .= $this->a;
if ($this->keptComment) {
$this->output = rtrim($this->output, "\n");
$this->output .= $this->keptComment;
$this->keptComment = '';
}
$this->lastByteOut = $this->a;
// fallthrough intentional
case self::ACTION_DELETE_A: // 2
$this->a = $this->b;
if ($this->a === "'" || $this->a === '"') { // string literal
$str = $this->a; // in case needed for exception
for (;;) {
$this->output .= $this->a;
$this->lastByteOut = $this->a;
$this->a = $this->get();
if ($this->a === $this->b) { // end quote
break;
}
if ($this->isEOF($this->a)) {
$byte = $this->inputIndex - 1;
throw new JSMin_UnterminatedStringException(
"JSMin: Unterminated String at byte {$byte}: {$str}");
}
$str .= $this->a;
if ($this->a === '\\') {
$this->output .= $this->a;
$this->lastByteOut = $this->a;
$this->a = $this->get();
$str .= $this->a;
}
}
}
// fallthrough intentional
case self::ACTION_DELETE_A_B: // 3
$this->b = $this->next();
if ($this->b === '/' && $this->isRegexpLiteral()) {
$this->output .= $this->a . $this->b;
$pattern = '/'; // keep entire pattern in case we need to report it in the exception
for (;;) {
$this->a = $this->get();
$pattern .= $this->a;
if ($this->a === '[') {
for (;;) {
$this->output .= $this->a;
$this->a = $this->get();
$pattern .= $this->a;
if ($this->a === ']') {
break;
}
if ($this->a === '\\') {
$this->output .= $this->a;
$this->a = $this->get();
$pattern .= $this->a;
}
if ($this->isEOF($this->a)) {
throw new JSMin_UnterminatedRegExpException(
"JSMin: Unterminated set in RegExp at byte "
. $this->inputIndex . ": {$pattern}");
}
}
}
if ($this->a === '/') { // end pattern
break; // while (true)
} elseif ($this->a === '\\') {
$this->output .= $this->a;
$this->a = $this->get();
$pattern .= $this->a;
} elseif ($this->isEOF($this->a)) {
$byte = $this->inputIndex - 1;
throw new JSMin_UnterminatedRegExpException(
"JSMin: Unterminated RegExp at byte {$byte}: {$pattern}");
}
$this->output .= $this->a;
$this->lastByteOut = $this->a;
}
$this->b = $this->next();
}
// end case ACTION_DELETE_A_B
}
}
/**
* @return bool
*/
protected function isRegexpLiteral()
{
if (false !== strpos("(,=:[!&|?+-~*{;", $this->a)) {
// we can't divide after these tokens
return true;
}
// check if first non-ws token is "/" (see starts-regex.js)
$length = strlen($this->output);
if ($this->a === ' ' || $this->a === "\n") {
if ($length < 2) { // weird edge case
return true;
}
}
// if the "/" follows a keyword, it must be a regexp, otherwise it's best to assume division
$subject = $this->output . trim($this->a);
if (!preg_match('/(?:case|else|in|return|typeof)$/', $subject, $m)) {
// not a keyword
return false;
}
// can't be sure it's a keyword yet (see not-regexp.js)
$charBeforeKeyword = substr($subject, 0 - strlen($m[0]) - 1, 1);
if ($this->isAlphaNum($charBeforeKeyword)) {
// this is really an identifier ending in a keyword, e.g. "xreturn"
return false;
}
// it's a regexp. Remove unneeded whitespace after keyword
if ($this->a === ' ' || $this->a === "\n") {
$this->a = '';
}
return true;
}
/**
* Return the next character from stdin. Watch out for lookahead. If the character is a control character,
* translate it to a space or linefeed.
*
* @return string
*/
protected function get()
{
$c = $this->lookAhead;
$this->lookAhead = null;
if ($c === null) {
// getc(stdin)
if ($this->inputIndex < $this->inputLength) {
$c = $this->input[$this->inputIndex];
$this->inputIndex += 1;
} else {
$c = null;
}
}
if (ord($c) >= self::ORD_SPACE || $c === "\n" || $c === null) {
return $c;
}
if ($c === "\r") {
return "\n";
}
return ' ';
}
/**
* Does $a indicate end of input?
*
* @param string $a
* @return bool
*/
protected function isEOF($a)
{
return ord($a) <= self::ORD_LF;
}
/**
* Get next char (without getting it). If is ctrl character, translate to a space or newline.
*
* @return string
*/
protected function peek()
{
$this->lookAhead = $this->get();
return $this->lookAhead;
}
/**
* Return true if the character is a letter, digit, underscore, dollar sign, or non-ASCII character.
*
* @param string $c
*
* @return bool
*/
protected function isAlphaNum($c)
{
return (preg_match('/^[a-z0-9A-Z_\\$\\\\]$/', $c) || ord($c) > 126);
}
/**
* Consume a single line comment from input (possibly retaining it)
*/
protected function consumeSingleLineComment()
{
$comment = '';
while (true) {
$get = $this->get();
$comment .= $get;
if (ord($get) <= self::ORD_LF) { // end of line reached
// if IE conditional comment
if (preg_match('/^\\/@(?:cc_on|if|elif|else|end)\\b/', $comment)) {
$this->keptComment .= "/{$comment}";
}
return;
}
}
}
/**
* Consume a multiple line comment from input (possibly retaining it)
*
* @throws JSMin_UnterminatedCommentException
*/
protected function consumeMultipleLineComment()
{
$this->get();
$comment = '';
for (;;) {
$get = $this->get();
if ($get === '*') {
if ($this->peek() === '/') { // end of comment reached
$this->get();
if (0 === strpos($comment, '!')) {
// preserved by YUI Compressor
if (!$this->keptComment) {
// don't prepend a newline if two comments right after one another
$this->keptComment = "\n";
}
$this->keptComment .= "/*!" . substr($comment, 1) . "*/\n";
} else if (preg_match('/^@(?:cc_on|if|elif|else|end)\\b/', $comment)) {
// IE conditional
$this->keptComment .= "/*{$comment}*/";
}
return;
}
} elseif ($get === null) {
throw new JSMin_UnterminatedCommentException(
"JSMin: Unterminated comment at byte {$this->inputIndex}: /*{$comment}");
}
$comment .= $get;
}
}
/**
* Get the next character, skipping over comments. Some comments may be preserved.
*
* @return string
*/
protected function next()
{
$get = $this->get();
if ($get === '/') {
switch ($this->peek()) {
case '/':
$this->consumeSingleLineComment();
$get = "\n";
break;
case '*':
$this->consumeMultipleLineComment();
$get = ' ';
break;
}
}
return $get;
}
}
class JSMin_UnterminatedStringException extends Exception
{
}
class JSMin_UnterminatedCommentException extends Exception
{
}
class JSMin_UnterminatedRegExpException extends Exception
{
}