TS2339: Property 'comparePassword' does not exist on type 'Model<Document, {}>'

Issue

I have defined a schema method by using this code. While I use in the service. It is showing a error.

// model

export interface User extends mongoose.Document {
    name: {
        type: String,
        required: [true, 'Please tell us your name.']
    },
    username: {
        type: String,
        required: [true, 'Please select a username.']
    },
    email: {
        type: String,
        required: [true, 'Please provide us your email.'],
        lowercase: true,
        unique: true,
        validate: [validator.isEmail, 'Please provide us your email.']
    },
    password: {
        type: String,
        required: [true, 'Please select a password.'],
        minLength: 8
        select: false
    },
    passwordConfirmation: {
        type: String,
        required: [true, 'Please re-enter your password.'],
        minLength: 8,
    },
    comparePassword(password: string): boolean
}

// method declared

userSchema.method('comparePassword', function (password: string): boolean {
    if (bcrypt.compareSync(password, this.password)) {
        return true;
    } else {
        return false;
    }
});

// service file

public loginUser  = async(req: Request, res: Response, next) => {
        const {username, password} = req.body;
        if(!username || !password){
            res.status(400).json({
                status: 'failed',
                message: 'Please provide username and password.'
            });
            return next(new AppError('Please provide username and password.', 400));
        } else {
            const person = await [![User][1]][1].comparePassword(password);
            const token = signToken(person._id);
            res.status(200).json({
                status: 'success',
                accessToken : token
            });
        }
    }

this line shows me the error.

const person = await User.comparePassword(password);

This is the screenshot in editor.

THis is the terminal screenshot

Can I know what is the problem here. I tried seeing the solution but could not find.

Solution

There was error in exporting the model.

export const User = mongoose.model<user>("User", userSchema);

And in the exporting interface add declare the function.

export interface user extends mongoose.Document {
    name: String,
    username: String,
    email: String,
    password: String,
    passwordConfirmation: String,
    comparePassword(candidatePassword: string): Promise<boolean>;
}

And the function is defined like this.

userSchema.methods.comparePassword = function (candidatePassword: string): Promise<boolean> {
    let password = this.password;
    return new Promise((resolve, reject) => {
        bcrypt.compare(candidatePassword, password, (err, success) => {
            if (err) return reject(err);
            return resolve(success);
        });
    });
};

Then there was error in calling the function person.comparePassword(). It should be called after finding the existing user. As @Mohammed Amir Ansari stated. the error was corrected and the actual error was exporting a model.

Answered By - Prashanth Damam