mocha test fail because this is undefined in mongoose pre validate hooks model (even without arrow function)

Question

I'm testing a post request that basically registers users to db. my mocha test fails because this is undefined when the pre validate hooks is triggered. I'm already using a normal function instead of an arrow function. It works perfectly in postman/insomnia . the problem occurs if I'm testing it through mocha.

userSchema.pre('validate', function(next) {

    if (this.password.split(' ').length > 1) {
        next(new Error('password can not contain a white space'));
    } else {
        next();
    }
});

Answer 1

For access to this it should be separate function

function preValidateFunction(next) {
    if (this.password.split(' ').length > 1) {
        next(new Error('password can not contain a white space'));
    } else {
        next();
    }
}

userSchema.pre('validate', preValidateFunction);