Simple Helper function to trim properties from MongoDB responses.

trimResponseES6.js

import _ from 'lodash'

/**
 * Trim Response function
 * Trim Object with given keys in Array
 * @param obj || array of objects
 * @param array
 * @return obj
**/

export function trimResponse( toTrim, array = []){

  // Default Trims
  let trimArray = ['_id', '__v']

  if(array.length > 0)
    trimArray = _.union(trimArray, array)

  // Check if toTrim is an Array of Objects
  if(Array.isArray(toTrim)){

    for(let i = 0; i < toTrim.length; i++){

      for(let j = 0; j < trimArray.length; j++){

        toTrim[i][trimArray[j]] = undefined

      }

    }

  }
  else{

    for(let i = 0; i < trimArray.length; i++){

      toTrim[trimArray[i]] = undefined

    }

  }

  // Return trimmed object
  return toTrim
}

trimResponseHelper.js

/**
 * Trim Response function
 * Trim MongoDB Object with given keys in Array
 * @param obj || array of objects
 * @param array
 * @return obj
**/
function trimResponse( toTrim, array ){
  
  // If no array passed, default to _id
  if(!array)
    array = ['_id']
  
  // Check if toTrim is an Array of Objects
  if(Array.isArray(toTrim)){
  
    for(var i = 0; i < toTrim.length; i++){
  
      for(var j = 0; j < array.length; j++){
  
        toTrim[i][array[j]] = undefined
  
      }
  
    }
  
  }
  else{
  
    for(var k = 0; k < array.length; k++){
  
      toTrim[array[k]] = undefined
  
    }
  
  }
 
  // Return trimmed object
  return toTrim
}

MongoDB response object trim.

ES6, Node, and lodash:
Also using _id and __v as default trims

import _ from 'lodash'

/**
 * Trim Response function
 * Trim Object with given keys in Array
 * @param obj || array of objects
 * @param array
 * @return obj
**/

export function trimResponse( toTrim, array = []){

  // Default Trims
  let trimArray = ['_id', '__v']

  if(array.length > 0)
    trimArray = _.union(trimArray, array)

  // Check if toTrim is an Array of Objects
  if(Array.isArray(toTrim)){

    for(let i = 0; i < toTrim.length; i++){

      for(let j = 0; j < trimArray.length; j++){

        toTrim[i][trimArray[j]] = undefined

      }

    }

  }

  else{

    for(let i = 0; i < trimArray.length; i++){

      toTrim[trimArray[i]] = undefined

    }

  }

  // Return trimmed object
  return toTrim
}