import { ValidationError } from 'class-validator';

export class ValidationErrorsFormatter {

/**

* @param {ValidationError[]} validationErrors

* @returns {string}

*/

public static format (validationErrors: ValidationError[]): string {

const errorsArray: string[] = [];

for (const error of validationErrors) {

errorsArray.push(ValidationErrorsFormatter.formatError(error));

}

return errorsArray.join('\n');

}

/**

* @param {ValidationError} validationError

* @returns {string}

*/

private static formatError (validationError: ValidationError): string {

const constraints: {[type: string]: string} = validationError.constraints;

let errorString: string = `\`${validationError.property}\` errors:\n`;

for (const constraint in constraints) {

if (!constraints.hasOwnProperty(constraint)) {

continue;

}

errorString += ` - ${constraints[constraint]}\n`;

}

return errorString;

}

}