How to decode last_error?

[mlafeldt]

Hey @geofmureithi,

It looks like Apalis always serializes the original error inside FailedError, e.g.

  "last_error": "{\"Err\":\"FailedError: unexpected error: Uncaught PermissionDenied: 'Deno.exit' is not allowed in this context.\\n    at Object.exit (ext:runtime/30_os.js:80:5)\\n    at <user_provided_script>:1:24\"}",

How are consumers of that string supposed to deserialize it? I want to access the original error type.

Is there a way to remove the error envelope? I added ErrorHandlingLayer, but it did not change how errors are serialized.

[mlafeldt]

I'm using the chore/v0.6.0 branch.

[geofmureithi]

This should be straight forward to resolve.

1. We will rename it to last_result to avoid the confusion.
2. You need to deserialize it as a Result<Res,Err> instead of Err, as seen here

Let me know if 2 works because it should work out of the box.

[geofmureithi]

Also, please note that the error type does not expect to be Serialize, but rather its converted to string and thats what is stored. I might work on something with the error handling layer to customize this.

[mlafeldt]

Oh, I'm already trying to deserialize it as Result. Works fine for the Ok case, but the FailedError envelope gives me trouble in case of Err.

[geofmureithi]

I think I can work on the error handling layer to allow using crates like https://docs.rs/serde-error/latest/serde_error/

[geofmureithi]

But its important to note this message on the crate:

In some other cases it may make sense to serialize the whole causality chain, but most often it makes most sense to just not serialize errors.

[mlafeldt]

Yeah, you're probably right. It looks like the original error isn't serialized, so the inner error is just converted using to_string.