* change normalize-js-tag so it marks the ctor prop

* add normalize-unresolved-prefix to fix up the cases we can't find
* add impl unit tests
* all externs infer tests passing again

Author: swannodette

src/main/clojure/cljs/analyzer.cljc

@@ -980,9 +980,10 @@
 (defn normalize-js-tag [x]
   ;; if not 'js, assume constructor
   (if-not (= 'js x)
-    (with-meta 'js
-      {:prefix (conj (->> (string/split (name x) #"\.")
-                       (map symbol) vec))})
+    (let [props  (->> (string/split (name x) #"\.") (map symbol))
+          [xs y] ((juxt butlast last) props)]
+      (with-meta 'js
+        {:prefix (vec (concat xs [(with-meta y {:ctor true})]))}))
     x))
 
 (defn ->type-set
@@ -1082,6 +1083,16 @@
                (recur (next pre) externs' top
                  (update ret :resolved conj x))))))))))
 
+(defn normalize-unresolved-prefix
+  [pre]
+  (cond-> pre
+    (< 1 (count pre))
+    (cond->
+      (-> pre pop peek meta :ctor)
+      (-> pop
+        (conj 'prototype)
+        (conj (peek pre))))))
+
 (defn has-extern?*
   [pre externs]
   (boolean (resolve-extern pre externs)))
@@ -3600,7 +3611,8 @@
       (let [pre (-> tag meta :prefix)]
         (when-not (has-extern? pre)
           (swap! env/*compiler* update-in
-            (into [::namespaces (-> env :ns :name) :externs] pre) merge {}))))
+            (into [::namespaces (-> env :ns :name) :externs]
+              (normalize-unresolved-prefix pre)) merge {}))))
     (case dot-action
       ::access (let [children [:target]]
                  {:op :host-field

src/test/clojure/cljs/externs_infer_tests.clj

@@ -23,6 +23,26 @@
    "goog.isArrayLike;" "Java.type;" "Object.out;" "Object.out.println;"
    "Object.error;" "Object.error.println;"])
 
+(deftest test-normalize-js-tag
+  (is (= 'js (ana/normalize-js-tag 'js)))
+  (is (= '[Foo] (-> 'js/Foo ana/normalize-js-tag meta :prefix)))
+  (is (true? (-> 'js/Foo ana/normalize-js-tag meta :prefix last meta :ctor)))
+  (is (= '[Foo Bar] (-> 'js/Foo.Bar ana/normalize-js-tag meta :prefix)))
+  (is (true? (-> 'js/Foo.Bar ana/normalize-js-tag meta :prefix last meta :ctor))))
+
+(deftest test-normalize-unresolved-prefix
+  (let [pre (-> (ana/normalize-js-tag 'js/Foo) meta :prefix (conj 'bar))]
+    (is (= '[Foo prototype bar] (ana/normalize-unresolved-prefix pre))))
+  (let [pre '[Foo bar]]
+    (is (= '[Foo bar] (ana/normalize-unresolved-prefix pre)))))
+
+(comment
+
+  (test/test-vars [#'test-normalize-js-tag])
+  (test/test-vars [#'test-normalize-unresolved-prefix])
+
+  )
+
 (deftest test-resolve-extern
   (let [externs
         (externs/externs-map
@@ -233,6 +253,15 @@
 
 (comment
 
+  (require '[clojure.java.io :as io]
+           '[cljs.closure :as cc])
+
+  (def externs
+    (-> (cc/js-source-file nil (io/file "src/test/externs/test.js"))
+      externs/parse-externs externs/index-externs))
+
+  (ana/resolve-extern '[Foo gozMethod] externs)
+
   (clojure.test/test-vars [#'test-type-hint-infer-unknown-method])
 
   )