JSON fixer

const jsonFixer = {
  fixJson: function (partialJson) {
    try {
      // Trim any whitespace from the beginning and end of the string
      let fixedJson = partialJson.trim();

      // Check if there are any unclosed quotes and close them if needed
      const openQuotes = (fixedJson.match(/"/g) || []).length % 2 !== 0;
      if (openQuotes) {
        fixedJson += '"';
      }

      // Try to parse the JSON, adding closing braces or brackets as needed
      while (true) {
        try {
          return JSON.parse(fixedJson);
        } catch (e) {
          // Count the number of opening and closing braces and brackets
          const unmatchedCurlyBraces =
            (fixedJson.match(/{/g) || []).length -
            (fixedJson.match(/}/g) || []).length;
          const unmatchedSquareBrackets =
            (fixedJson.match(/\[/g) || []).length -
            (fixedJson.match(/]/g) || []).length;

          // If there are unmatched curly braces, add a closing curly brace
          if (unmatchedCurlyBraces > 0) {
            fixedJson += "}";
          }
          // If there are unmatched square brackets, add a closing square bracket
          else if (unmatchedSquareBrackets > 0) {
            fixedJson += "]";
          }
          // If the JSON is still invalid, assume there is a missing key-value pair
          else {
            if (fixedJson[fixedJson.length - 1] === ",") {
              fixedJson += '"UNKNOWN_KEY":"VALUE"';
            } else {
              fixedJson += ',"UNKNOWN_KEY":"VALUE"';
            }
          }
        }
      }
    } catch (e) {
      throw new Error("Unable to fix JSON string");
    }
  },
};

module.exports = jsonFixer;