the if statement is not working inspite of it's value being true while used with an mongoose ob-CodePudding

so I am creating an bidding app, this is the schema for the bidding model

const bidSchema = new mongoose.Schema({
    
    name: String,
    price : Number,
    description: String,
    location: String,
    specilization: String,
    image: String,
    createdUser: {
      type: mongoose.Schema.Types.ObjectId,
      ref: User
    },
    highestBidder: {
      highBidderName: {
        type: mongoose.Schema.Types.ObjectId,
        ref: User
      },
      highPrice: Number,
      
     },
     previousBidders: [{previousName: {
      type: mongoose.Schema.Types.ObjectId,
      ref: User
     } , previousPrice: Number}],
     isClosed: {
       type: Boolean,
       enum:[true]
     }
     
})

this is my bid route in which a bid will get added

route.post('/:id/submitbid',isloggedin, async (req,res) => {
    
    const {id} = req.params

const bids = await Bid.findById(id)

if(! bids.highestBidder){

    bids.highestBidder.highBidderName = req.user._id
    bids.highestBidder.highPrice = req.body.highPrice
   await bids.save()
   console.log('if worked')
    res.redirect(`bids/${bids._id}`)
    

} else {

   const previousName = bids.highestBidder.highBidderName
   const previousPrice = bids.highestBidder.highPrice

   bids.highestBidder.highBidderName = req.user._id
   bids.highestBidder.highPrice = req.body.highPrice
    
   bids.previousBidders.push({previousName,previousPrice})
   console.log('else worked')
   await bids.save()
   res.redirect(`/bids/${bids._id}`)

}

})

initially , the bids.highestBidder part don't contain anything, so when I console logged the bid object before the execution of the /:id/submit route and this is what I got in the console.

{
  _id: new ObjectId("616944da40c3b2ac3779f93b"),
  name: 'gratus',
  price: 10,
  description: ';fdja;dfja;ldf;a',
  location: 'india',
  image: 'https://source.unsplash.com/random/200x200?sig=1',
  previousBidders: [],
  createdUser: {
    _id: new ObjectId("61687ab4a79b1fa356b9fca5"),
    email: '[email protected]',
    username: 'gratus',
    __v: 0
  },
  __v: 0

as one can see that there is no bids.highestBidder exist, so when I execute the /:id/submitbid post route, the if statement should execute, but this is what I am getting in the console after executing that route

else worked

I have no idea why else is working , and the problem with is that if I now console logged my bid object, this is what I am getting

else worked
{
  highestBidder: {
    highBidderName: {
      _id: new ObjectId("61687ab4a79b1fa356b9fca5"),
      email: '[email protected]',
      username: 'gratus',
      __v: 0
    },
    highPrice: 5
  },
  _id: new ObjectId("616944da40c3b2ac3779f93b"),
  name: 'gratus',
  price: 10,
  description: ';fdja;dfja;ldf;a',
  location: 'india',
  image: 'https://source.unsplash.com/random/200x200?sig=1',
  previousBidders: [ { _id: new ObjectId("616944e740c3b2ac3779f943") } ],
  createdUser: {
    _id: new ObjectId("61687ab4a79b1fa356b9fca5"),
    email: '[email protected]',
    username: 'gratus',
    __v: 0
  },
  __v: 1
}

it is creating an empty previousBidders array, which breaks my whole application. I would really appreciate any solution.

CodePudding user response：

Mongoose model instances are not ordinary objects. They generally have special methods to generate the json output you see when performing a console.log. This means the field very well may be present, but simply not rendered in the console output due to the fact that it's sub-properties are not set.

Since highestBidder has sub-properties, likely the default boolean if-check you are performing returns true due to those properties. You may be able to avoid this via:

if ( !bids.highestBidder || !bids.highestBidder.highBidderName ) {
 ...
}

What this achieves is that if highestBidder is ever not declared, it immediately jumps to execute the code inside the if. Otherwise it will also check to see if the highestBidderName property has a value and execute the if code block if none is found. This way you avoid ghost subproperties added by mongoose from affecting your conditional results.

There's possibly a more elegant solution than this, but this is a quick and easy way.