[V5] How to validate nullable field?

[woubuc]

Validator schema:

name: schema.string.optional({ trim: true }),
description: schema.string.optional(),

Route handler in controller:

let body = await request.validate(Validator);

let item = await Item.findOrFail(params.id);
item.merge(body);
await item.save();

Now whenever I send { description: null } or { description: "" } (any falsy value) to the update request, the validator strips that field entirely. So it doesn't set the description field to null even though the column is nullable and I explicitly sent null in the request.

How can I make the validator return this field as null when it's set to a null value? Is there something like schema.string.nullable()?

[thetutlage]

Inside config/app.ts file under the validator object, you can define the option existsStrict = true to allow empty strings. Do note, the null and undefined both are considered missing and ignored.

If the validator object inside the config file is missing, then you can declare it as follows

export const validator: ValidatorConfig = {
  existsStrict: true,
}

And then make sure you are running @adonisjs/[email protected]

[woubuc]

null and undefined both are considered missing and ignored

This is kind of the problem I'm having. I want null to mean 'set this nullable field to null (i.e. the value that I sent)' and not 'this field is missing so don't do anything'. That's what undefined is for imo.

The strict option gets me part of the way there (so I can workaround it) but not entirely.

[thetutlage]

Agree. I believe, we have to introduce another option to allow null values. I will look into it in couple of days and get back to you

[sn0rcha]

Any update on this @thetutlage?

[emiliosanches]

@thetutlage any update?

[lukfor85]

Any update please? I desperately need this tbh.

[sn0rcha]

I have the same problem. I need to pass null as a value when clearing the field but currently the validator strips it.

[mcordoba]

same problem here, any update?

[RomainLanz]

I am working on it this weekend. 👍🏻

[sockenklaus]

Inside config/app.ts file under the validator object, you can define the option existsStrict = true to allow empty strings. Do note, the null and undefined both are considered missing and ignored.

If the validator object inside the config file is missing, then you can declare it as follows

export const validator: ValidatorConfig = {
  existsStrict: true,
}

And then make sure you are running @adonisjs/[email protected]

@loranbraga
Did you read this?

[rodrigorz]

To work with nullableAndOptional i have to disable empty strings existsStrict: false inside config/app.ts.
Because the birth_date: schema.date.nullableAndOptional() rule throws a date.format error when receive an empty string.

I am using Adonis as an API, all requests is a JSON or MULTIPART. Why BodyParserJSONConfig do not have convertEmptyStringsToNull? Only FORM / MULTIPART have it.

[thetutlage]

Because with JSON requests you can control what you are sending. Whereas, convertEmptyStringsToNull is meant to overcome the browsers behavior of sending empty string when a form field has no value.

If you are self constructing the JSON, then you can do this on the client.

[filev-svt]

I agree partially - I do have control over the JSON requests, however I would have to convert every single text input from an empty string to null manually (using react-hook-form), which would be far more difficult than just setting convertEmptyStringsToNull to true in the bodyparser.ts for JSON requests. I feel like it would be much more flexible to at least have the option to set this configuration.

[thetutlage]

We added it for v6. Lemme see if we can back port it for current version too