pika-iconv-lite

pika-iconv-lite is an ES6 module fork of iconv-lite. It matches the original described below, except that it is loaded via module import instead of Node's commonjs require(). See the updated code snippets in the README below for the new import syntax.

Pure JS character encoding conversion

• Doesn't need native code compilation. Works on Windows and in sandboxed environments like Cloud9.
• Used in popular projects like Express.js (body_parser), Grunt, Nodemailer, Yeoman and others.
• Faster than node-iconv (see below for performance comparison).
• Intuitive encode/decode API
• Streaming support for Node v0.10+
• [Deprecated] Can extend Node.js primitives (buffers, streams) to support all iconv-lite encodings.
• In-browser usage via Browserify (~180k gzip compressed with Buffer shim included).
• Typescript type definition file included.
• React Native is supported (need to explicitly npm install two more modules: buffer and stream).
• License: MIT.

Usage

Basic API

import iconv from 'pika-iconv-lite';
 
// Convert from an encoded buffer to js string.
console.log(iconv.decode(new Buffer([0x68, 0x65, 0x6c, 0x6c, 0x6f]), 'win1251'));
 
// Convert from js string to an encoded buffer.
console.log(iconv.encode("Sample input string", 'win1251'));
 
// Check if encoding is supported
console.log(iconv.encodingExists("us-ascii"));

Streaming API (Node v0.10+)

 
// Decode stream (from binary stream to js strings)
http.createServer(function(req, res) {
    var converterStream = iconv.decodeStream('win1251');
    req.pipe(converterStream);
 
    converterStream.on('data', function(str) {
        console.log(str); // Do something with decoded strings, chunk-by-chunk.
    });
});
 
// Convert encoding streaming example
fs.createReadStream('file-in-win1251.txt')
    .pipe(iconv.decodeStream('win1251'))
    .pipe(iconv.encodeStream('ucs2'))
    .pipe(fs.createWriteStream('file-in-ucs2.txt'));
 
// Sugar: all encode/decode streams have .collect(cb) method to accumulate data.
http.createServer(function(req, res) {
    req.pipe(iconv.decodeStream('win1251')).collect(function(err, body) {
        assert(typeof body == 'string');
        console.log(body); // full request body string
    });
});

[Deprecated] Extend Node.js own encodings

NOTE: This doesn't work on latest Node versions. See details.

// After this call all Node basic primitives will understand iconv-lite encodings.
iconv.extendNodeEncodings();
 
// Examples:
buf = new Buffer(str, 'win1251');
buf.write(str, 'gbk');
str = buf.toString('latin1');
assert(Buffer.isEncoding('iso-8859-15'));
Buffer.byteLength(str, 'us-ascii');
 
http.createServer(function(req, res) {
    req.setEncoding('big5');
    req.collect(function(err, body) {
        console.log(body);
    });
});
 
fs.createReadStream("file.txt", "shift_jis");
 
// To remove extensions
iconv.undoExtendNodeEncodings();

Supported encodings

• All node.js native encodings: utf8, ucs2 / utf16-le, ascii, binary, base64, hex.
• Additional unicode encodings: utf16, utf16-be, utf-7, utf-7-imap.
• All widespread singlebyte encodings: Windows 125x family, ISO-8859 family, IBM/DOS codepages, Macintosh family, KOI8 family, all others supported by iconv library. Aliases like 'latin1', 'us-ascii' also supported.
• All widespread multibyte encodings: CP932, CP936, CP949, CP950, GB2312, GBK, GB18030, Big5, Shift_JIS, EUC-JP.

See all supported encodings on wiki.

Most singlebyte encodings are generated automatically from node-iconv. Thank you Ben Noordhuis and libiconv authors!

Multibyte encodings are generated from Unicode.org mappings and WHATWG Encoding Standard mappings. Thank you, respective authors!

Encoding/decoding speed

Comparison with node-iconv module (1000x256kb, on MacBook Pro, Core i5/2.6 GHz, Node v0.12.0). Note: your results may vary, so please always check on your hardware.

operation             iconv@2.1.4   iconv-lite@0.4.7
----------------------------------------------------------
encode('win1251')     ~96 Mb/s      ~320 Mb/s
decode('win1251')     ~95 Mb/s      ~246 Mb/s

BOM handling

• Decoding: BOM is stripped by default, unless overridden by passing stripBOM: false in options (f.ex. iconv.decode(buf, enc, {stripBOM: false})). A callback might also be given as a stripBOM parameter - it'll be called if BOM character was actually found.
• If you want to detect UTF-8 BOM when decoding other encodings, use node-autodetect-decoder-stream module.
• Encoding: No BOM added, unless overridden by addBOM: true option.

UTF-16 Encodings

This library supports UTF-16LE, UTF-16BE and UTF-16 encodings. First two are straightforward, but UTF-16 is trying to be smart about endianness in the following ways:

• Decoding: uses BOM and 'spaces heuristic' to determine input endianness. Default is UTF-16LE, but can be overridden with defaultEncoding: 'utf-16be' option. Strips BOM unless stripBOM: false.
• Encoding: uses UTF-16LE and writes BOM by default. Use addBOM: false to override.

Other notes

When decoding, be sure to supply a Buffer to decode() method, otherwise bad things usually happen.
Untranslatable characters are set to � or ?. No transliteration is currently supported.
Node versions 0.10.31 and 0.11.13 are buggy, don't use them (see #65, #77).

Testing

$ git clone git@github.com:ashtuchkin/iconv-lite.git
$ cd iconv-lite
$ npm install
$ npm test
    
$ # To view performance: 
$ node test/performance.js
 
$ # To view test coverage: 
$ npm run coverage
$ open coverage/lcov-report/index.html

Adoption