Mongoose SchemaType.prototype.validators Property

Mongoose is a MongoDB object modeling and handling for a node.js environment. The Mongoose SchemaType validators property is used to get the validators applied on a schema path of a mongoose schema.

Syntax:

SchemaType.prototype.validators

Creating node application And Installing Mongoose:

Step 1: Create a node application using the following command:

mkdir folder_name
cd folder_name
npm init -y
touch main.js

Step 2: After completing the Node.js application, Install the required module using the following command:

npm install mongoose

Project Structure: It will look like the following.

Example 1: In this example, we will use this method to log the validators applied on the “name” mongoose schema path.

Filename: main.js

Javascript

// Importing the module
const mongoose = require('mongoose')

// Creating the connection
mongoose.connect('mongodb://localhost:27017/query-helpers',
    {
        dbName: 'event_db',
        useNewUrlParser: true,
        useUnifiedTopology: true
    }, err => err ? console.log(err)
        : console.log('Connected to database'));

const personSchema = new mongoose.Schema({
    name: {
        type: String,
        required: true
    },
    age: {
        type: Number,
    }
});

const Person = mongoose.model('Person', personSchema);

(async () => {
    const validators = personSchema.path('name').validators
    console.log({ validators });
})()

Step to Run Application: Run the application using the following command from the root directory of the project:

node main.js

Output:

Example 2: In this example, we will use this method to validate a particular age using the validators applied on the “age” mongoose schema path.

Filename: main.js

Javascript

// Importing the module
const mongoose = require('mongoose')

// Creating the connection
mongoose.connect('mongodb://localhost:27017/query-helpers',
    {
        dbName: 'event_db',
        useNewUrlParser: true,
        useUnifiedTopology: true
    }, err => err ? console.log(err)
        : console.log('Connected to database'));

const personSchema = new mongoose.Schema({
    name: {
        type: String,
    },
    age: {
        type: Number,
        min: 20
    }
});

const Person = mongoose.model('Person', personSchema);

(async () => {
    const validators = personSchema.path('age').validators
    const res = validators[0].validator(28)
    console.log({res});
})()

Step to Run Application: Run the application using the following command from the root directory of the project:

node main.js

Output:

Reference: https://mongoosejs.com/docs/api/schematype.html#schematype_SchemaType-validators