replaceNullsWithEmptyStrings.js

// Recursive function to replace null values with empty strings in a JSON object.
// Courtesy of Tony Germano from Mirth Slack aka @tonygermano on GitHub
// Usage: replaceNullsWithEmptyStrings(msg);

function replaceNullsWithEmptyStrings(obj) {
  return JSON.parse(JSON.stringify(obj), (key, value) => (value === null ? "" : value));
}

// Example usage:
var msgWithNulls = {
  name: "John",
  age: null,
  address: {
    street: "123 Main St",
    city: null
  }
};
var msgWithoutNulls = replaceNullsWithEmptyStrings(msgWithNulls);
logger.info(msgWithoutNulls);

// Result:
// {
//   name: "John",
//   age: "",
//   address: {
//     street: "123 Main St",
//     city: ""
//   }
// }