CLJS-1968: Enable calling JS modules that export a single function

Author: anmonteiro

src/main/clojure/cljs/analyzer.cljc

@@ -691,8 +691,9 @@
   [module]
   ;; we need to check both keys and values of the JS module index, because
   ;; macroexpansion will be looking for the provided name - António Monteiro
-  (-> (into #{} (mapcat identity) (get-in @env/*compiler* [:js-module-index]))
-    (contains? module)))
+  (contains?
+    (into #{} (mapcat identity) (get-in @env/*compiler* [:js-module-index]))
+    (str module)))
 
 (defn confirm-var-exists
   ([env prefix suffix]
@@ -711,7 +712,7 @@
                 (not (loaded-js-ns? env prefix))
                 (not (and (= 'cljs.core prefix) (= 'unquote suffix)))
                 (nil? (gets @env/*compiler* ::namespaces prefix :defs suffix))
-                (not (js-module-exists? (str prefix))))
+                (not (js-module-exists? prefix)))
        (missing-fn env prefix suffix)))))
 
 (defn confirm-var-exists-throw []
@@ -746,7 +747,7 @@
              ;; macros may refer to namespaces never explicitly required
              ;; confirm that the library at least exists
              #?(:clj (nil? (util/ns->source ns-sym)))
-             (not (js-module-exists? (str ns-sym))))
+             (not (js-module-exists? ns-sym)))
     (warning :undeclared-ns env {:ns-sym ns-sym})))
 
 (defn core-name?
@@ -921,6 +922,13 @@
            (some? (gets @env/*compiler* ::namespaces (-> env :ns :name) :imports sym))
            (recur env (gets @env/*compiler* ::namespaces (-> env :ns :name) :imports sym) confirm)
 
+           (or (js-module-exists? s)
+               (js-module-exists? (resolve-ns-alias env s)))
+           (let [module (or (gets @env/*compiler* :js-module-index s)
+                            (resolve-ns-alias env s))]
+             {:name (symbol module)
+              :ns   'js})
+
            :else
            (let [cur-ns (-> env :ns :name)
                  full-ns (cond