* change inference to that constructors return themselves as the type…

… not js/Function

* add corresponding js-tag test

src/main/clojure/cljs/analyzer.cljc

@@ -1079,9 +1079,16 @@
    (js-tag pre tag-type externs externs))
   ([pre tag-type externs top]
    (when-let [[p externs' :as me] (find externs (first pre))]
-     (let [tag (-> p meta tag-type)]
+     (let [info (meta p)
+           tag  (get info tag-type)]
        (if (= (count pre) 1)
-         (when tag (symbol "js" (str (alias->type tag tag))))
+         (when tag
+           ;; If we have a JS constructor don't return the type as
+           ;; js/Function as this isn't useful in type inference
+           ;; instead just return the constructor
+           (if-let [ctor (:ctor info)]
+             (symbol "js" (str ctor))
+             (symbol "js" (str (alias->type tag tag)))))
          (or (js-tag (next pre) tag-type externs' top)
              (js-tag (into '[prototype] (next pre)) tag-type (get top tag) top)))))))
 

src/test/clojure/cljs/externs_infer_tests.clj

@@ -48,7 +48,8 @@
     (is (= 'js/Console (ana/js-tag '[console] :tag externs)))
     (is (= 'js/Function (ana/js-tag '[console log] :tag externs)))
     (is (= 'js/Boolean (ana/js-tag '[Number isNaN] :ret-tag externs)))
-    (is (= 'js/Foo (ana/js-tag '[baz] :ret-tag externs)))))
+    (is (= 'js/Foo (ana/js-tag '[baz] :ret-tag externs)))
+    (is (= 'js/Number (ana/js-tag '[Number] :tag externs)))))
 
 (defn infer-test-helper
   [{:keys [forms externs warnings warn js-dependency-index node-module-index with-core? opts]}]