Cron job that checks for date expiration

Question

Let's take the following example:

I have two mongoDb collections named user and products. A user can add unlimited products, but each product expires in 5 days and it has to be dynamically removed from the db when it expires.

user.js

const UserSchema = mongoose.Schema(
  {
    username: { type: String },
    email: { type: String },
    timezone: { type: String },
    products: [{ type: Schema.Types.ObjectId, ref: 'Products' }]
  }
)

export default mongoose.model('User', UserSchema);

products.js

var RunSchema = mongoose.Schema(
  {
    name: { type: String },
    completedAt: { type: Date }
  }
)

export default mongoose.model('Run', RunSchema);

Is there another way of doing this in nodejs rather than having one cron job which runs every day and checks all documents from the products collection?

I'm thinking about a solution where a each user can have a cron job that starts once they add a product...

Answer 1

It is too late answer the question even though , I would like to give alternative operation with minimal operation and without Cron Job

If you want remove product document after creation of 5 day's interval then you can achieve with 2 line of code in model itself. You have add one property i.e(expireAt) in model and pass the interval to that property with help of moment npm library

    var RunSchema = mongoose.Schema(
  {
    name: { type: String },
    completedAt: { type: Date },
    expireAt: {
         type: Date,
         default: moment(new Date()).add("5", "days"),
         expires: 432000000
   }
  }
)

export default mongoose.model('Run', RunSchema);

after creation of product document date and time . it will automatically remove document from collection of every 5 days of interval.