While implementing some authentication logic on an adonis project. I needed at some point to throw a specific http code status In this case a 403 forbidden.

Adonis thanks to it’s global exceptions handler will manage exceptions for you.

Route.get("dashboard", async ({ auth, response }) => {
  //If someCode comes to throw an error,
  //then adonis global exception listener will handle it
  await auth.Authenfication();

  // business logic
});

//Instead of usually
Route.get("dashboard", async ({ auth, response }) => {
  if (!auth.isLoggedIn) {
    return response.status(401).send("Unauthenticated");
  }

  // business logic
});

Adonis provides an idiomatic way to raise custom exceptions manually.
Using adonis custom exceptions, it’s possible to throw custom exception to the global exception listener at any time.
You can use adonis CLI to init your custom exception as follows

node ace make:exception Forbidden
# CREATE: app/Exceptions/ForbiddenException.ts

Then add static context to the created custom exception if necessary.

//app/Exceptions/ForbiddenException.ts
import { Exception } from "@adonisjs/core/build/standalone";

export default class ForbiddenException extends Exception {
  constructor() {
    const message = "Access forbidden";
    const status = 403;
    const errorCode = "E_FORBIDDEN";

    super(message, status, errorCode);
  }
}

Finally use it inside any route handler

import ForbiddenException from "App/Exceptions/ForbiddenException";

Route.get("dashboard", async ({ auth, response }) => {
  if (someCondition) {
    throw new ForbiddenException();
  }

  // business logic
});