Update nrepl to handle describe and eldoc (#51)

* Update nrepl to handle describe and eldoc

See https://github.com/babashka/sci.nrepl/issues/2

* Update changelog

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 - Use `window.location.hostname` for WebSocket connection
 - Upgrade sci configs to `bf8d209e`
+- Update nrepl implementation, implement `eldoc` (`info`, `lookuup`)
 
 ## v0.5.14 (2023-01-05)
 

src/scittle/nrepl.cljs

@@ -2,14 +2,17 @@
   (:require
    [clojure.edn :as edn]
    [sci.nrepl.completions :refer [completions]]
+   [sci.nrepl.info :refer [info]]
    [scittle.core :refer [!last-ns eval-string !sci-ctx]]))
 
 (defn nrepl-websocket []
   (.-ws_nrepl js/window))
 
-(defn nrepl-reply [{:keys [id session]} payload]
+(defn nrepl-reply [{:keys [id session]} {:keys [ns] :as payload}]
   (.send (nrepl-websocket)
-         (str (assoc payload :id id :session session :ns (str @!last-ns)))))
+         (str
+          (let [ns (or ns (str @!last-ns))]
+            (assoc payload :id id :session session :ns ns)))))
 
 (defn handle-nrepl-eval [{:keys [code] :as msg}]
   (let [[kind val] (try [::success (eval-string code)]
@@ -25,11 +28,46 @@
         (nrepl-reply msg {:ex (pr-str val)
                           :status ["error" "done"]})))))
 
+(defn handle-nrepl-info [msg]
+  (let [info (info (assoc msg :ctx @!sci-ctx))]
+    (nrepl-reply msg info)))
+
+(declare ops)
+
+(defn
+  handle-describe
+  [msg]
+  (nrepl-reply
+   msg
+   {:versions {"scittle-nrepl" {"major" "0"
+                                "minor" "0"
+                                "incremental" "1"}}
+    :ops (zipmap
+          (map
+           name
+           (concat
+            (keys ops)
+            ;; sci.nrepl browser_server.clj handles:
+            #{:clone :load-file}
+            ;; we are lying about close?
+            #{"close"}))
+          (repeat {}))
+    :status ["done"]}))
+
+(def ops
+  "Operations supported by the nrepl server."
+  {:eval handle-nrepl-eval
+   :info handle-nrepl-info
+   :eldoc handle-nrepl-info
+   :lookup handle-nrepl-info
+   :describe handle-describe
+   :complete (fn [msg] (let [completions (completions (assoc msg :ctx @!sci-ctx))]
+                         (nrepl-reply msg completions)))})
+
 (defn handle-nrepl-message [msg]
-  (case (:op msg)
-    :eval (handle-nrepl-eval msg)
-    :complete (let [completions (completions (assoc msg :ctx @!sci-ctx))]
-                (nrepl-reply msg completions))))
+  (if-let [handler (ops (:op msg))]
+    (handler msg)
+    (nrepl-reply (merge msg {:status ["error" "done"] :err "unkown-op"}) (assoc msg :ctx @!sci-ctx))))
 
 (defn ws-url [host port path]
   (str "ws://" host ":" port "/" path))