eng/strip-json-comments.js

/**
 * Copied from https://github.com/sindresorhus/strip-json-comments/blob/main/index.js
 */

const singleComment = Symbol("singleComment");
const multiComment = Symbol("multiComment");
const stripWithoutWhitespace = () => "";
const stripWithWhitespace = (string, start, end) => string.slice(start, end).replace(/\S/g, " ");

const isEscaped = (jsonString, quotePosition) => {
  let index = quotePosition - 1;
  let backslashCount = 0;

  while (jsonString[index] === "\\") {
    index -= 1;
    backslashCount += 1;
  }

  return Boolean(backslashCount % 2);
};

module.exports = (jsonString, options = {}) => {
  if (typeof jsonString !== "string") {
    throw new TypeError(`Expected argument \`jsonString\` to be a \`string\`, got \`${typeof jsonString}\``);
  }

  const strip = options.whitespace === false ? stripWithoutWhitespace : stripWithWhitespace;

  let insideString = false;
  let insideComment = false;
  let offset = 0;
  let result = "";

  for (let i = 0; i < jsonString.length; i++) {
    const currentCharacter = jsonString[i];
    const nextCharacter = jsonString[i + 1];

    if (!insideComment && currentCharacter === '"') {
      const escaped = isEscaped(jsonString, i);
      if (!escaped) {
        insideString = !insideString;
      }
    }

    if (insideString) {
      continue;
    }

    if (!insideComment && currentCharacter + nextCharacter === "//") {
      result += jsonString.slice(offset, i);
      offset = i;
      insideComment = singleComment;
      i++;
    } else if (insideComment === singleComment && currentCharacter + nextCharacter === "\r\n") {
      i++;
      insideComment = false;
      result += strip(jsonString, offset, i);
      offset = i;
      continue;
    } else if (insideComment === singleComment && currentCharacter === "\n") {
      insideComment = false;
      result += strip(jsonString, offset, i);
      offset = i;
    } else if (!insideComment && currentCharacter + nextCharacter === "/*") {
      result += jsonString.slice(offset, i);
      offset = i;
      insideComment = multiComment;
      i++;
      continue;
    } else if (insideComment === multiComment && currentCharacter + nextCharacter === "*/") {
      i++;
      insideComment = false;
      result += strip(jsonString, offset, i + 1);
      offset = i + 1;
      continue;
    }
  }

  return result + (insideComment ? strip(jsonString.slice(offset)) : jsonString.slice(offset));
};