@sebastianwessel/quickjs/dist/esm/modules/buffer.js

A typescript package to execute JavaScript and TypeScript code in a WebAssembly QuickJS sandbox

export default `
import { TextEncoder, TextDecoder } from 'node:util'

class Buffer extends Uint8Array {
  constructor(arg, encoding) {
    if (typeof arg === 'number') {
        super(arg);
    } else if (typeof arg === 'string') {
        super(Buffer._stringToBytes(arg, encoding));
    } else if (arg instanceof ArrayBuffer) {
        super(new Uint8Array(arg));
    } else if (Array.isArray(arg) || arg instanceof Uint8Array) {
        super(arg);
    } else {
        throw new TypeError('Invalid argument type');
    }
  }

  static from(arg, encoding) {
    if (typeof arg === 'string') {
        return new Buffer(Buffer._stringToBytes(arg, encoding));
    } else if (Array.isArray(arg) || arg instanceof Uint8Array) {
        return new Buffer(arg);
    } else if (arg instanceof ArrayBuffer) {
        return new Buffer(new Uint8Array(arg));
    } else {
        throw new TypeError('Invalid argument type');
    }
  }

  static alloc(size) {
      return new Buffer(size);
  }

  static allocUnsafe(size) {
      return new Buffer(size);
  }

  static concat(buffers, totalLength) {
    if (!Array.isArray(buffers)) {
        throw new TypeError('Argument must be an array of Buffers');
    }
    if (buffers.length === 0) {
        return Buffer.alloc(0);
    }
    if (totalLength === undefined) {
        totalLength = buffers.reduce((acc, buf) => acc + buf.length, 0);
    }
    const result = Buffer.allocUnsafe(totalLength);
    let offset = 0;
    for (const buf of buffers) {
        result.set(buf, offset);
        offset += buf.length;
    }
    return result;
  }

  toString(encoding) {
    if (encoding === 'base64') {
        return Buffer._bytesToBase64(this);
    } else {
        return Buffer._bytesToString(this, encoding);
    }
  }

  static _stringToBytes(string, encoding) {
    if (encoding === 'base64') {
        return Buffer._base64ToBytes(string);
    } else {
        return new TextEncoder().encode(string);
    }
  }

  static _bytesToString(bytes, encoding) {
    if (encoding === 'utf-8' || encoding === undefined) {
        return new TextDecoder(encoding).decode(bytes);
    } else {
        throw new TypeError('Unsupported encoding');
    }
  }

  static _base64ToBytes(base64) {
    const binaryString = atob(base64);
    const length = binaryString.length;
    const bytes = new Uint8Array(length);
    for (let i = 0; i < length; i++) {
        bytes[i] = binaryString.charCodeAt(i);
    }
    return bytes;
  }

  static _bytesToBase64(bytes) {
    let binary = '';
    for (let i = 0; i < bytes.length; i++) {
        binary += String.fromCharCode(bytes[i]);
    }
    return btoa(binary);
  }
}

globalThis.Buffer = Buffer

export { Buffer }

export default Buffer;
`;