Merge pull request #134 from ZJONSSON/open-extract

Add `Open.extract` method

README.md

@@ -301,5 +301,16 @@ async function main() {
 main();
 ```
 
+### Open.[method].extract()
+
+The directory object returned from `Open.[method]` provides an `extract` method which extracts all the files to a specified `path`, with an optional `concurrency` (default: 1).
+
+Example (with concurrency of 5):
+
+```js
+unzip.Open.file('path/to/archive.zip')
+  .then(d => d.extract({path: '/extraction/path', concurrency: 5}));
+```
+
 ## Licenses
 See LICENCE

lib/Open/directory.js

@@ -5,6 +5,8 @@ var Promise = require('bluebird');
 var BufferStream = require('../BufferStream');
 var parseExtraField = require('../parseExtraField');
 var Buffer = require('../Buffer');
+var path = require('path');
+var Writer = require('fstream').Writer;
 
 var signature = Buffer.alloc(4);
 signature.writeUInt32LE(0x06054b50,0);
@@ -71,6 +73,32 @@ module.exports = function centralDirectory(source, options) {
 
       source.stream(vars.offsetToStartOfCentralDirectory).pipe(records);
 
+      vars.extract = function(opts) {
+        if (!opts || !opts.path) throw new Error('PATH_MISSING');
+        return vars.files.then(function(files) {
+          return Promise.map(files, function(entry) {
+            if (entry.type == 'Directory') return;
+
+            // to avoid zip slip (writing outside of the destination), we resolve
+            // the target path, and make sure it's nested in the intended
+            // destination, or not extract it otherwise.
+            var extractPath = path.join(opts.path, entry.path);
+            if (extractPath.indexOf(opts.path) != 0) {
+              return;
+            }
+            var writer = opts.getWriter ? opts.getWriter({path: extractPath}) :  Writer({ path: extractPath });
+
+            return new Promise(function(resolve, reject) {
+              entry.stream(opts.password)
+                .on('error',reject)
+                .pipe(writer)
+                .on('close',resolve)
+                .on('error',reject);
+            });
+          },{concurrency: opts.concurrency || 1});
+        });
+      };
+
       vars.files = Promise.mapSeries(Array(vars.numberOfRecords),function() {
         return records.pull(46).then(function(data) {    
           var vars = binary.parse(data)

test/open-extract.js

@@ -0,0 +1,34 @@
+'use strict';
+
+var test = require('tap').test;
+var path = require('path');
+var temp = require('temp');
+var dirdiff = require('dirdiff');
+var unzip = require('../');
+
+
+test("extract compressed archive with open.file.extract", function (t) {
+  var archive = path.join(__dirname, '../testData/compressed-standard/archive.zip');
+
+  temp.mkdir('node-unzip-2', function (err, dirPath) {
+    if (err) {
+      throw err;
+    }
+    unzip.Open.file(archive)
+      .then(function(d) {
+        return d.extract({path: dirPath});
+      })
+      .then(function() {
+        dirdiff(path.join(__dirname, '../testData/compressed-standard/inflated'), dirPath, {
+          fileContents: true
+        }, function (err, diffs) {
+          if (err) {
+            throw err;
+          }
+          t.equal(diffs.length, 0, 'extracted directory contents');
+          t.end();
+        });
+      });
+
+  });
+});