ValidationError

DTO that represents a structured validation failure. Thrown by every safe runner on RequestBuilder when the response carries a code / error / error_description envelope plus a nested errors object.

ValidationError is structurally similar to RequestError but does not extend it — it is a separate DTO with its own errors and params fields.

Importing

import { ValidationError } from '@basmilius/http-client';

Constructor

new ValidationError(
    code: number,
    error: string,
    errorDescription: string,
    errors: Record<string, ValidationError>,
    params: Record<string, string | number | boolean>
)

Argument	Type	Description
code	number	Application-specific numeric code.
error	string	Machine-readable error key.
errorDescription	string	Human-readable description.
errors	Record<string, ValidationError>	Per-field validation errors, possibly nested.
params	Record<string, string | number | boolean>	Parameters used by the description (for templating).

Properties

• code — number. Read-only.
• error — string. Read-only.
• errorDescription — string. Read-only.
• errors — Record<string, ValidationError>. Read-only. Each entry is itself a ValidationError so trees of nested forms (address.street, address.city) can be rendered without manual reshaping.
• params — Record<string, string | number | boolean>. Read-only. Useful for substitutions in i18n strings.

Methods

ValidationError is decorated with @dto and inherits clone(), fill() and toJSON().

Walking the error tree

import { ValidationError } from '@basmilius/http-client';

function flatten(prefix: string, error: ValidationError, into: Record<string, string>): void {
    if (error.errorDescription) {
        into[prefix || error.error] = error.errorDescription;
    }

    for (const key in error.errors) {
        flatten(prefix ? `${prefix}.${key}` : key, error.errors[key], into);
    }
}

Example

import { isValidationError } from '@basmilius/http-client';

try {
    await userService.create(form);
} catch (error) {
    if (isValidationError(error)) {
        for (const field in error.errors) {
            console.warn(field, error.errors[field].errorDescription);
        }

        return;
    }

    throw error;
}

See also

• RequestError — non-validation failures.
• HttpAdapter.parseValidationError
• Error handling guide
• isValidationError