mongocat/src/utils/flatten.ts

✨ Mongocat 😺 is easy to use, configuration based Denormalization mongoose plugin for read heavy applications. Mongocat reduces write complexity too.

import { Types } from 'mongoose';

// Declare a flatten function that takes
// object as parameter and returns the
// flatten object
export const flattenObj = (ob: Record<string, any>) => {
  // The object which contains the
  // final result
  const result: { [key: string]: any } = {};

  // loop through the object "ob"
  for (const i in ob) {
    // We check the type of the i using
    // typeof() function and recursively
    // call the function again
    if (
      !(ob[i] instanceof Types.ObjectId) &&
      typeof ob[i] === 'object' &&
      !Array.isArray(ob[i])
    ) {
      const temp = flattenObj(ob[i]);
      for (const j in temp) {
        // Store temp in result
        result[i + '.' + j] = temp[j];
      }
    }

    // Else store ob[i] in result directly
    else {
      result[i] = ob[i];
    }
  }
  return result;
};