Check schema optional options should include optional and checkFalsy

After extensive searching (and checking the TypeScript types), I can’t find how to set the value of the optional validator and set checkFalsy to true at the same time using the checkSchema validation method.

The documentation says that a field’s validation can be made optional by including optional: true in the ValidationParamSchema, but so far as I can tell there isn’t a way to set optional to false and set checkFalsy to true. My request is to add a key to ValidatorOptions.OptionalOptions that allows the user to set whether or not the schema field validation should be optional, and if not optional, to check falsy values.

Here’s my setup:

// Passed as middleware into route

public static checkSearch: ValidationChain[] = [
        ...checkSchema({
            pageIndex: SearchValidator.pageIndex(),
            pageSize: SearchValidator.pageSize(),
            order: SearchValidator.order(),
            term: SearchValidator.term(true) // true is passed to indicate the field should be optional
        })
    ];

// Called in checkSchema()

public static term = (isOptional: boolean = false): ValidationParamSchema => {
        return {
            in: 'body',
            errorMessage: 'Term is invalid',
            optional: {
                KEY: isOptional // here I want to be able to set whether or not the field is optional
                checkFalsy: true,
            },
            isLength: {
                errorMessage: 'Term not provided',
                options: {
                    min: 1
                }
            }
        };
    }

Thanks for any ideas and help you can offer.

[gustavohenke]

What are you looking for exactly, @elboletaire? I see you want to make your field somehow optional. But it is not clear how.

Please note that notEmpty is not a validator on the check API yet. It is on the legacy API though. So, to check that a string has some chars in it, you should use isEmpty: { negated: true }.

And to make it optional, know that optional: true is telling express-validator to skip validation if the value is undefined. Setting checkFalsy: true will also skip validation when the value is any of the falsy ones in JS: undefined, null, false, 0 or '' (empty string).

I’m closing this issue since we don’t seem to have uncovered any bug.

[elboletaire]

Sincerely? I’m not sure right now 😅

Everything started because I wanted just one validation to check two fields (I’ve ended up splitting the logic). Then the issue was just trying to find out the correct combination between optional and isEmpty, but I think that with what you said I’m able to go forward now.

Thanks!