(ns pathom-boundary-interface-errors
  (:require
    [cognitect.transit :as transit]
    [com.wsscode.pathom3.connect.operation :as pco]
    [com.wsscode.pathom3.connect.indexes :as pci]
    [com.wsscode.pathom3.interface.smart-map :as psm]
    [com.wsscode.pathom3.interface.eql :as p.eql]
    [com.wsscode.pathom3.connect.built-in.resolvers :as pbir]
    [com.wsscode.pathom3.error :as p.error])
  (:import
    [ ByteArrayOutputStream ByteArrayInputStream]))

(def indexes
  (pci/register
    [(pbir/constantly-fn-resolver ::throw-error (fn [_] (throw (ex-info "Error" {}))))]))

(def pathom
  (p.eql/boundary-interface
    (merge
      indexes
      {::p.error/lenient-mode? true})))

(defn ->transit
  [form]
  (let [out (ByteArrayOutputStream. 4096)
        writer (transit/writer out :json)]
    (transit/write writer form)
    (.toString out)))

; :com.wsscode.pathom3.error/exception cannot be serialized to Transit
; Throws:
; Not supported: class clojure.lang.ExceptionInfo
(->transit (pathom [::throw-error]))

what version are you using? I see something different on my end, but there is also a bug I notice

but on my end, the bug is that if you have ::p.error/lenient-mode? true the boundary interface will return a blank output (on latest pathom)

instead of using at the env level, you can set it on the request level as well

like this:

(pathom {:pathom/eql [::throw-error]
                      :pathom/lenient-mode? true})

right now, sending it there works, I'm going to fix pathom in a bit

Currently on v2022.01.09-alpha

So the Right Thing to get things over the wire is to remove any :com.wsscode.pathom3.error/node-exception from the result?

you should bump Pathom, you are using an old version

in the new versions it already does some error processing that makes it suitable to go over the wire

I'm finishing the fix to the latest, should be out today

current latest is 2022.03.07-alpha

Thank you @U066U8JQJ! We have errors flowing over the wire

Works like a charm, thank you @U066U8JQJ