Core: Handle Exceptions by Error Code

[MohamedElidrissi]

Why this feature is required (specific use-cases will be appreciated)?

Currently, there are two ways to handle Exceptions. The first way is to register a single Exception handler using Exception.handle(name, callback), the second is to create a global Exception handler by running adonis make:ehandler. Now what if I want to handle an Exception with a specific code and leave the rest to the default exception handler that Adonis ships with?
For instance, there are many types of HttpExceptions, each with a different code but I want to handle only the one with E_GUEST_ONLY so I tried the following:

// start/hooks.js
const { hooks } = require('@adonisjs/ignitor')

hooks.after.providersBooted(() => {
  const Exception = use('Exception')

  // redirect to / when the user is logged in
  Exception.handle('HttpException', async (error, { response }) => {
    if (error.code === 'E_GUEST_ONLY') {
      response.redirect('/')
    }
    return
  })
})

I would expect to redirect to / only when error.code is E_GUEST_ONLY but fallback to the development exception page on E_ROUTE_NOT_FOUND for example. But the current behaviour is it redirects to / in both cases.

Have you tried any other work arounds?

I tried creating a global handler with adonis make:ehandler but that doesn't suit my need as I want to handle a single exception by code and let Adonis handle the rest.

Are you willing to work on it with little guidance?

If given a starting point, sure.

[RomainLanz]

Hey @MohamedElidrissi! 👋

The global exception handler is extending the BaseExceptionHandler, therefore you can call its handle method.

return super.handle(...arguments)

Example in our blog demo: https://github.com/AdonisCommunity/adonis-blog-demo/blob/master/app/Exceptions/Handler.js#L30

[MohamedElidrissi]

@RomainLanz Oh I don't know how I missed that part, thanks! But still I think having all exception handling done in one class is not super great, if there are multiple exceptions to handle it will be filled with if statements. I guess it would've been better it there was an API like Exception.handle(exceptionName, code, handler).
Anyway, thanks for the help.

[thetutlage]

You can write abstractions to avoid multiple if statements. I don't think, we will add another way to handle exceptions at this time.

Thanks 😄

[lock[bot]]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.