Node.js jszip library to extract

Question

I am writing some node code, and using jszip to zip and unzip some files. I know how to zip, but cannot figure out how to unzip, or decompress. There are a couple of links on stackoverflow that do not work. Anyone has any solution? Following is what I have tried

var fs = require('fs');
var JSZip   = require('jszip');
var zipName = "C:/test.zip";
var unzip = "C:/unzip";


fs.readFile(zipName, function (err, data) {
    if (err) throw err;
    var zip = new JSZip();
    zip.folder(unzip).load(data);
});

Wild

Answer 1

JSZip has no method to write files on the disk. To do it, you need to iterate over zip.files :

var path = require("path");
Object.keys(zip.files).forEach(function(filename) {
  var content = zip.files[filename].asNodeBuffer();
  var dest = path.join(unzip, filename);
  fs.writeFileSync(dest, content);
}

Inside a zip file, folders are represented with a forward slash '/', I think that path.join() will create a correct path but I can't test this.

Avner

hello my good sir, it looks as if you forgot a closing parenthesis – Labium

Answer 2

Probably was due to my wrong implementation of asNodeBuffer and my lack of experience with JS, but I kept extracting the files wrongly. I wanted to share what end up working for me, I tested it with a 250+ MB file.

...
fs.readFile(tmpFilePath, function (err, data) {
    if (err) {
        throw err;
    }
    logger.debug('[method] Before extracting file...');
    JSZip.loadAsync(data).then(function (zip) {
        var files = Object.keys(zip.files);
        logger.debug('[method] files to be created ' + files.length);
        // in my case, the folders where not being created while "inflating" the content. created the folders in a separated loop 
        // O(n) for those geeks on complexity. 
        createDirectories(files);
        createFiles(files, zip, someOtherFunctionReference);
    }).catch(function (err) {
        deferred.reject(err);
    });
});
...

/**
 * Sync opperation to create the folders required for the files.
 * @param files
 */
function createDirectories(files) {
    files.forEach(function (filename) {
        var dest = path.join(folderName, filename);
        ensureDirectoryExistence(dest);
    });
}

/**
 * recursive create directory function
 * @param filePath
 * @returns {boolean}
 */
function ensureDirectoryExistence(filePath) {
    var dirname = path.dirname(filePath);
    if (fs.existsSync(dirname)) {
        return true;
    }
    ensureDirectoryExistence(dirname);
    fs.mkdirSync(dirname);
}

/**
 * Create files sync or blocking
 * @param files
 * @param zip
 * @param cb
 */
function createFiles(files, zip, cb) {
    try {
        var countFilesCreated = 0;
        files.forEach(function (filename) {
            var dest = path.join(folderName, filename);
            // skip directories listed
            if (dest.charAt(dest.length - 1) === '/') {
                countFilesCreated++;
                return;
            }
            return zip.file(filename).async('nodebuffer').then(function(content){
                // var content = zip.files[filename].nodeStream();
                fs.writeFileSync(dest, content);
                countFilesCreated++;
                // proably someone with more experience in JS can implement a promice like solution. 
                // I thought that in here instead of the counter we coud use an indexOf to return an error in case not all the elements where created correctly. 
                // but if a file throw an error, its handled by the catch ... 
                if (countFilesCreated >= files.length) {
                    logger.debug('All files created!!');
                    cb();
                }
            });
        });
    } catch (err) {
        throw err;
    }
}

I hope this helps.

Stator