Jarves\Utils::compressJs PHP Method

    public function compressJs(array $assets, $targetPath)
    {
        $oFile = $targetPath;
        $files = [];
        $md5String = '';
        $newestMTime = 0;
        foreach ($assets as $assetPath) {
            $path = $this->jarves->resolveWebPath($assetPath);
            $files[] = '--js ' . escapeshellarg($path);
            $mtime = filemtime($path);
            $newestMTime = max($newestMTime, $mtime);
            $md5String .= ">{$path}.{$mtime}<";
        }
        $sourceMap = $oFile . '.map';
        $cmdTest = 'java -version 2>&1';
        $closure = 'vendor/google/closure-compiler/compiler.jar';
        $compiler = escapeshellarg(realpath('../' . $closure));
        $cmd = 'java -jar ' . $compiler . ' --js_output_file ' . escapeshellarg('web/' . $oFile);
        $returnVal = 0;
        $debugMode = false;
        $handle = @fopen($oFile, 'r');
        $fileUpToDate = false;
        $md5Line = '//' . md5($md5String) . "\n";
        if ($handle) {
            $line = fgets($handle);
            fclose($handle);
            if ($line === $md5Line) {
                $fileUpToDate = true;
            }
        }
        if ($fileUpToDate) {
            return true;
        } else {
            if (!$debugMode) {
                exec($cmdTest, $outputTest, $returnVal);
            }
            if (0 === $returnVal) {
                $cmd .= ' --create_source_map ' . escapeshellarg('web/' . $sourceMap);
                $cmd .= ' --source_map_format=V3';
                $cmd .= ' ' . implode(' ', $files);
                $cmd .= ' 2>&1';
                $output = [];
                exec($cmd, $output, $returnVal);
                if (0 === $returnVal) {
                    //                    if (false === strpos($output, 'ERROR - Parse error')) {
                    $content = file_get_contents('web/' . $oFile);
                    $sourceMapUrl = '//@ sourceMappingURL=' . basename($sourceMap);
                    $content = $md5Line . $content . $sourceMapUrl;
                    file_put_contents('web/' . $oFile, $content);
                    return true;
                    //                    }
                }
            }
            $content = '';
            foreach ($assets as $assetPath) {
                $content .= "\n/* {$assetPath} */\n\n";
                $path = $this->jarves->resolveWebPath($assetPath);
                $content .= file_get_contents($path);
            }
            if ($content) {
                $this->webFilesystem->write($oFile, $content);
                return true;
            }
            return false;
        }
    }