@mptool/encoder

TextEncoder / TextDecoder implementations for mini-program environments that lack GBK / GB18030 support, plus the standard UTF-8 implementation.

Installation

npm i @mptool/encoder
# Equivalent: pnpm add @mptool/encoder

Importing the package does not modify globals; import the classes from the package and use them as needed (mount them globally yourself if you need a polyfill).

Supported encodings

Encoding	Available labels (case-insensitive)
UTF-8	utf-8, utf8, unicode-1-1-utf-8
GBK	gbk, gb2312, gb_2312, gb_2312-80, csgb2312, chinese, x-gbk, etc.
GB18030	gb18030

The label list matches the WHATWG Encoding standard. GB2312 is served through the GBK labels; there is no separate GB2312 encoding.

TextDecoder

import { TextDecoder } from "@mptool/encoder";

const decoder = new TextDecoder("gbk");

decoder.encoding; // "gbk"
decoder.decode(new Uint8Array([0xd6, 0xd0, 0xce, 0xc4])); // "中文"

Constructor options:

• fatal: when true, invalid bytes throw a TypeError; otherwise the replacement character � is emitted
• ignoreBOM: when true, the BOM is kept

TextEncoder

TextEncoder encodes as UTF-8 by default; as a non-standard extension (WHATWG's TextEncoder only supports UTF-8), it also accepts other encoding labels:

import { TextEncoder } from "@mptool/encoder";

new TextEncoder().encode("中文"); // UTF-8
new TextEncoder("gbk").encode("中文"); // Uint8Array [0xd6, 0xd0, 0xce, 0xc4]
new TextEncoder("gb18030").encode("中文");

• An unknown label throws a RangeError
• new TextEncoder(label) is not a function call: new is required
• The encoding property returns the current encoding ("utf-8", "gbk" or "gb18030")