CLJS-1409: Allow basic type checking of protocols

include :protocols in the deftype & defrecord ASTs.

emit function(){} instead of {} for protocol to make Closure
happy.

emit @implements for each protocol implemented by a
type.

Author: swannodette

src/main/clojure/cljs/analyzer.cljc

@@ -1963,7 +1963,8 @@
                                  :shadow (m fld)}))
                        {} (if (= :defrecord* op)
                             (concat fields '[__meta __extmap ^:mutable __hash])
-                            fields))]
+                            fields))
+        protocols (-> tsym meta :protocols)]
     (swap! env/*compiler* update-in [::namespaces (-> env :ns :name) :defs tsym]
            (fn [m]
              (let [m (assoc (or m {})
@@ -1973,9 +1974,11 @@
                        :record (= :defrecord* op))]
                (merge m
                       (dissoc (meta tsym) :protocols)
-                      {:protocols (-> tsym meta :protocols)}
+                      {:protocols protocols}
                       (source-info tsym env)))))
-    {:op op :env env :form form :t t :fields fields :pmasks pmasks :body (analyze (assoc env :locals locals) body)}))
+    {:op op :env env :form form :t t :fields fields :pmasks pmasks
+     :protocols (disj protocols 'cljs.core/Object)
+     :body (analyze (assoc env :locals locals) body)}))
 
 (defmethod parse 'deftype*
   [_ env form _ _]

src/main/clojure/cljs/compiler.cljc

@@ -1042,11 +1042,13 @@
   (load-libs uses requires (:use reloads)))
 
 (defmethod emit* :deftype*
-  [{:keys [t fields pmasks body]}]
+  [{:keys [t fields pmasks body protocols]}]
   (let [fields (map munge fields)]
     (emitln "")
     (emitln "/**")
     (emitln "* @constructor")
+    (doseq [protocol protocols]
+      (emitln " * @implements {" (munge (str protocol)) "}"))
     (emitln "*/")
     (emitln (munge t) " = (function (" (comma-sep fields) "){")
     (doseq [fld fields]
@@ -1057,11 +1059,13 @@
     (emit body)))
 
 (defmethod emit* :defrecord*
-  [{:keys [t fields pmasks body]}]
+  [{:keys [t fields pmasks body protocols]}]
   (let [fields (concat (map munge fields) '[__meta __extmap __hash])]
     (emitln "")
     (emitln "/**")
     (emitln "* @constructor")
+    (doseq [protocol protocols]
+      (emitln " * @implements {" (munge (str protocol)) "}"))
     (emitln "*/")
     (emitln (munge t) " = (function (" (comma-sep fields) "){")
     (doseq [fld fields]

src/main/clojure/cljs/core.cljc

@@ -1895,7 +1895,7 @@
                                sigs))))]
     `(do
        (set! ~'*unchecked-if* true)
-       (def ~psym (js-obj))
+       (def ~psym (~'js* "function(){}"))
        ~@(map method methods)
        (set! ~'*unchecked-if* false))))