Validating Promises¶

Basic Promise Validation¶

If your object contains properties with Promise-returned values that should be validated, you need to use the @ValidatePromise() decorator:

import { ValidatePromise, Min } from 'class-validator';

export class Post {
    @Min(0)
    @ValidatePromise()
    userId: Promise<number>;
}

Combining with Nested Validation¶

It works great with the @ValidateNested decorator:

import { ValidateNested, ValidatePromise } from 'class-validator';

export class Post {
    @ValidateNested()
    @ValidatePromise()
    user: Promise<User>;
}

Async Validation¶

When validating promises, the validation itself becomes asynchronous:

import { validate } from 'class-validator';

let post = new Post();
post.userId = Promise.resolve(1);

validate(post).then(errors => {
    // handle errors
});