express-validator : How to validate "start date" is before "end date"

Question

I am using express-validator to do my server validation and I have come across a little trouble with my date validation. I am trying to validate that my Start Date is before my End Date. I am currently using this:

check('taskStartDate', { isBefore : ('taskEndDate' === undefined ) })
.isBefore('taskEndDate').withMessage('Start Date must be before End Date')

However, the problem with that is no matter what date I input into my form, whether the start date is before or after the end date, I get my implemented message 'Start Date must be before End Date'. I don't know how else to go about doing this besides a custom validator, which if that is the recommended way, I would appreciate any guidance on how to go about writing the custom validation. I also tried to include sanitization like so:

check('taskStartDate').isBefore(sanitizeBody('taskEndDate').toDate())
.withMessage( 'Start Date must be before End Date.')

but that did not work either. Any help would be greatly appreciated!

Answer 1

express-validator uses underlying validator.js, so all validator.js middlewares are available in express-validator as well.

check [validator.js]: https://github.com/validatorjs/validator.js#validators for complete list

there is .isAfter() and isBefore().

you can implement this way

check('dateOfMissing', 'Date cannot be in future').Before('dateOfMissing', ['timeinpast']),
check('dateOfMissing', 'Date cannot be in future').isAfter('dateOfMissing', ['time in future']);

default is now (current date)

Answer 2

here's a custom validator for checking if the entered date of birth(dob) is valid or not , ie, before today's date.

check('dob').custom(value=>{
    let enteredDate=new Date(value);
    let todaysDate=new Date();
    if(enteredDate>todaysDate){
        throw new Error("Invalid Date");
    }
    return true;
})

dob= name of input field for date of birth

Answer 3

Yes, using a custom validator is the way to go when you want to check a value against another in the request.

You would be interested in the following combo of sanitizers and validator (sanitizers run before the validators, so you can get the value as Date objects when using them):

[
  sanitize('taskEndDate').toDate(),
  check('taskStartDate').toDate().custom((startDate, { req }) => {
    if (startDate.getTime() >= req.body.taskEndDate.getTime()) {
      throw new Error('start date must be before end date');
    }
    return true;
  })
]

Look at the docs for further examples.

Answer 4

As @gustavohenke wrote, you should create custom validator. Code below is for express-validator version 13.7.0. Main difference to @gustavohenke example is changed validation function to check() and in current version this function must return true at the end.

[
    check('end').toDate(),
    check('start').toDate().custom((startDate, { req }) => {
        if (startDate.getTime() > req.body.end.getTime()) {
            throw new Error('start date must be before end date');
        }
        return true
    })
];