LaravelValidationError.ts

LaravelValidationError.ts

/**

This is a typical Laravel API JSON validation error.

{
  "message": "The given data was invalid.",
  "errors": {
    "name": [
      "The name field is required."
    ],
    "email": [
      "The email field is required."
    ]
  }
}

And this is the interface in Typescript for this error. And a small helper class. 
*/

export interface LaravelValidationError {
	message: string,
	errors: {
		[field: string]: string[]
	}
}

export default class ValidationError extends Error {
	private _data: LaravelValidationError;

	constructor(data: LaravelValidationError) {
		super(data.message);
		this._data = data;
	}

	public static isValidationError(error: any): error is LaravelValidationError {
		return (error.message && error.errors);
	}

	public getHTML() {
		let str = `<p>${this._data.message}</p>`;
		str += "<ul>";
		for (const field of Object.keys(this._data.errors)) {
			for (const errorString of this._data.errors[field]) {
				str += `<li>${errorString}</li>`;
			}
		}
		str += "</ul>";
		return str;
	}
}