@fairfox/zws/dist/index.js

Zero-width steganography utilities for invisibly embedding data in text using Unicode zero-width characters

// src/index.ts
var START_MARKER = "​‌";
var END_MARKER = "‌​";
var ZERO_BIT = "​";
var ONE_BIT = "‌";
var MAX_DATA_LENGTH = 100;
var MAX_ENCODED_LENGTH = MAX_DATA_LENGTH * 16;
function hasEmbeddedData(text) {
  if (typeof text !== "string")
    return false;
  return text.includes(START_MARKER);
}
function embed(text, data) {
  const normalizedText = typeof text !== "string" ? String(text || "") : text;
  const normalizedData = typeof data !== "string" ? String(data || "") : data;
  if (hasEmbeddedData(normalizedText)) {
    return normalizedText;
  }
  try {
    const encodedData = encodeData(normalizedData);
    const marker = START_MARKER + encodedData + END_MARKER;
    const sentenceEnd = normalizedText.search(/[.!?]\s/);
    if (sentenceEnd !== -1) {
      const insertPos = sentenceEnd + 1;
      return normalizedText.substring(0, insertPos) + marker + normalizedText.substring(insertPos);
    }
    return normalizedText + marker;
  } catch (error) {
    console.warn("Failed to embed data:", error instanceof Error ? error.message : String(error));
    return normalizedText;
  }
}
function extract(text) {
  if (typeof text !== "string")
    return "";
  if (!hasEmbeddedData(text)) {
    return "";
  }
  try {
    const pattern = new RegExp(`${START_MARKER}([${ZERO_BIT}${ONE_BIT}]*)${END_MARKER}`);
    const match = text.match(pattern);
    if (!match) {
      return "";
    }
    return decodeData(match[1] || "");
  } catch (error) {
    console.warn("Data extraction failed:", error);
    return "";
  }
}
function getCleanText(text) {
  if (typeof text !== "string")
    return String(text || "");
  return text.replace(new RegExp(`${START_MARKER}[${ZERO_BIT}${ONE_BIT}]*${END_MARKER}`, "g"), "");
}
function encodeData(data) {
  if (data.length > MAX_DATA_LENGTH) {
    throw new Error(`Data too long: ${data.length} characters. Maximum allowed: ${MAX_DATA_LENGTH} characters.`);
  }
  for (let i = 0;i < data.length; i++) {
    const codePoint = data.codePointAt(i) || 0;
    if (codePoint > 65535) {
      throw new Error(`Invalid character in data: "${data[i]}" (U+${codePoint.toString(16).toUpperCase()}). Data must use UTF-8 safe characters only.`);
    }
  }
  const binary = Array.from(data).map((char) => char.charCodeAt(0).toString(2).padStart(16, "0")).join("");
  return binary.split("").map((bit) => bit === "0" ? ZERO_BIT : ONE_BIT).join("");
}
function decodeData(encodedBinary) {
  if (encodedBinary.length > MAX_ENCODED_LENGTH) {
    throw new Error(`Encoded data too long: ${encodedBinary.length} characters. Maximum allowed: ${MAX_ENCODED_LENGTH} characters.`);
  }
  const cleanBinary = encodedBinary.split("").filter((char) => char === ZERO_BIT || char === ONE_BIT).map((char) => char === ZERO_BIT ? "0" : "1").join("");
  const chars = [];
  for (let i = 0;i < cleanBinary.length; i += 16) {
    const charBinary = cleanBinary.substring(i, i + 16);
    if (charBinary.length === 16) {
      const codePoint = Number.parseInt(charBinary, 2);
      chars.push(String.fromCharCode(codePoint));
    }
  }
  return chars.join("");
}
var zws = {
  START_MARKER,
  END_MARKER,
  ZERO_BIT,
  ONE_BIT,
  MAX_DATA_LENGTH,
  MAX_ENCODED_LENGTH,
  hasEmbeddedData,
  embed,
  extract,
  getCleanText,
  encodeData,
  decodeData
};
var src_default = zws;
export {
  src_default as default
};