Best possible way to handle validation

[dark jasper]

Exception filters - Throwing standard exceptions

[vast valley]

You need to create exception filter for necord context and catch validation error

[true jacinth]

@vast valley not possible through exception filter as it will run after the guard, I want that the error shuold be geneerated before as the field is required in the payload

[vast valley]

Exception filter catch all exceptions in execution (guards, pipes,interceptors your main code)

[vast valley]

Also you can read necord validation article

[true jacinth]

I am using Global Pipes to do the validation of the dto , as the data coming from the client side have some field, and that field is getting modified or added to the request object (field is coming from the db service) through the interceptor, as interceptor runs before the pipe so the pipe is not giving me error that the field is missing, please suggest me some ideas to implement the validation of the dto.

[dark jasper]

Techniques - Validation

[true jacinth]

@vast valley I need the error as the client hits the request since the field is required

[vast valley]

Problem is interceptor which override some fields?

[true jacinth]

@vast valley yes

[vast valley]

What dto you have?

[true jacinth]

I am having a value field in it

[vast valley]

Do you use ValidationPipe from nestjs?

[true jacinth]

yes i have used

[vast valley]

Can you show example of your dto?

[true jacinth]

app.useGlobalPipes(
new ValidationPipe({
whitelist: true, // Strip properties that are not in the DTO
forbidNonWhitelisted: true, // Throw error for properties not in the DTO
transform: true, // Don't transform payloads
}),
);

app.useGlobalFilters(new AllExceptionsFilter());

[vast valley]

It’s looks good

[true jacinth]

It is something like this

export class TagDto{
@IsNotEmpty()
@IsObject()
value: object
}

[vast valley]

TagDto without any fields?

So, ok, how do you use it in controller?

I mean declaration

[true jacinth]

@Post()
async tag(@Body() tagDto: TagDto){}

[vast valley]

I guess it’s wrong channel for it question, post it to #1025199348096700476

It’s necord-related (lib for discord bots) channel

[true jacinth]

I have posted it but very less response, Thank you for your time @vast valley

[vast valley]

I can advise you not to mutate the body object into another enhancers

That's the only way I can help.

[true jacinth]

@vast valley I have an Idea like what if I build a custom middleware to validate the dto's it will work fine, but then the usecase of global pipes will be gone void

[vast valley]

I don’t think so

[true jacinth]

@vast valley help me out with some examples or explanations