CLJS-3236: defprotocol externs inference warnings

in defprotocol macro mark protocol properties, ignore them

Author: swannodette

src/main/clojure/cljs/analyzer.cljc

@@ -3351,7 +3351,8 @@
 ;; (. (...) -p)
 (defmethod build-dot-form [::expr ::property ()]
   [[target prop _]]
-  {:dot-action ::access :target target :field (-> prop name (.substring 1) symbol)})
+  {:dot-action ::access :target target
+   :field (with-meta (-> prop name (.substring 1) symbol) (meta prop))})
 
 ;; (. o -p <args>)
 (defmethod build-dot-form [::expr ::property ::list]
@@ -3410,7 +3411,8 @@
                               update-in [:prefix] (fnil conj '[Object]) prop))
                        nil)]
     (when (and (not= 'constructor prop)
-               (not (string/starts-with? (str prop) "cljs$")))
+               (not (string/starts-with? (str prop) "cljs$"))
+               (not (-> prop meta :protocol-method)))
       ;; Adding to Object
       (when (= 'Object (first (-> tag meta :prefix)))
         (warning :infer-warning env

src/main/clojure/cljs/core.cljc

@@ -2109,7 +2109,8 @@
                                      ;; check protocol property on object (first check executed)
                                      check
                                      `(if (and (not (nil? ~fsig))
-                                               (not (nil? (. ~fsig ~(symbol (core/str "-" slot)))))) ;; Property access needed here.
+                                               ;; Property access needed here.
+                                               (not (nil? (. ~fsig ~(with-meta (symbol (core/str "-" slot)) {:protocol-method true})))))
                                         (. ~fsig ~slot ~@sig)
                                         (~dyn-name ~@sig))]
                             `(~sig ~check)))
@@ -2160,7 +2161,8 @@
                            (defn ~fname
                              ~@(map (core/fn [sig]
                                       (expand-sig dyn-name
-                                        (symbol (core/str slot "$arity$" (count sig)))
+                                        (with-meta (symbol (core/str slot "$arity$" (count sig)))
+                                          {:protocol-method true})
                                         sig))
                                  sigs)))))]
     `(do