why.clj

(ns backend.service-test
  (:require [om.next :as om :refer [defui]]
            [midje.sweet :refer :all]
            [clojure.test :refer [deftest]]))

(defmulti om-read om/dispatch)
(defmethod om-read :default
  [_ k _]
  (throw (ex-info (str "read: " k) {:k k})))

(defmethod om-read :db/id
  [{:keys [target]} k _]
  {:value (get target k)})

(defmethod om-read :user/name
  [{:keys [target]} k _]
  {:value (get target k)})

(defmethod om-read :user/id
  [{:keys [target]} k _]
  {:value (get target k)})

(defmethod om-read :me
  [{:keys [state query parser] :as env} k v]
  ;; Why parser returns '[]'
  {:value (parser env query (get @state k))})

(def parser
  (om/parser
    {:read   om-read}))

(deftest recursive-read
  (let [state (atom {:me {:db/id 1 :user/name "abc" :user/id "1"}})
        env {:state state}]
    (fact
      "why it fail?"
      (parser env [{:me [:db/id :user/name]}])
      ;; actual => {:me []} 
      => {:me {:db/id 1 :user/name "abc"}})))