Custom error status on AuthenticationStrategy

Is your feature request related to a problem? Please describe. I’m developing a custom AuthenticationStrategy. It’s working fine on the optimistic case. But on my case I need to return custom errors message when a login fail, such as when the account is blocked.

But since the method authenticate could return only two types (User on success case, and false on fail case), I don’t have a way to send a detailed error message to frontend display.

Describe the solution you’d like We could change the authenticate to return something like that:

Promise<{
  success: true
  user: User
} |
{
  success: false
  error: string
}>

It’s pretty flexible and type safe.

Describe alternatives you’ve considered Another way, in order to not have break change, is changing the return type to Promise<User | false | string> - but it could be confused about what string means.

[michaelbromley]

Oh this is a bit of a pain, but because some types are shared by both the Admin and Shop APIs, they get generated in both the generated-types.ts file (Admin API) and generated-shop-types.ts file (Shop API). Then when you try to assign one to another TS complains. It can be quite tricky to solve (you’ll see some cases in the BaseAuthResolver where I needed to import both types and make a union of them). If you can’t figure it out, throw in an as any and add a TODO: correct typings and I’ll take a look. Don’t let it hold up the rest of the work.

[michaelbromley]

Yes, that would be helpful!

A few pointers:

I’d add a authenticationError: String! field to: https://github.com/vendure-ecommerce/vendure/blob/db1893a9bf46fc95f918e9f99db2e4472d5a6c9d/packages/core/src/api/schema/common/common-types.graphql#L201-L204

Then if you run the codegen script it will update the generated class in this file and the constructor will now expect an argument for the authenticationError value.

Then in the AuthService you’d add a typeof user === 'string' check here and pass the value to the error constructor: https://github.com/vendure-ecommerce/vendure/blob/db1893a9bf46fc95f918e9f99db2e4472d5a6c9d/packages/core/src/service/services/auth.service.ts#L57-L60

Also adding an e2e test to https://github.com/vendure-ecommerce/vendure/blob/master/packages/core/e2e/authentication-strategy.e2e-spec.ts would be great.