CLJS-1895: Externs inference needs to support user supplied externs

Author: dnolen

src/main/clojure/cljs/build/api.clj

@@ -190,7 +190,8 @@
    (build source opts
      (if-not (nil? env/*compiler*)
        env/*compiler*
-       (env/default-compiler-env opts))))
+       (env/default-compiler-env
+         (closure/add-externs-sources opts)))))
   ([source opts compiler-env]
    (doseq [[unknown-opt suggested-opt] (util/unknown-opts (set (keys opts)) closure/known-opts)]
      (when suggested-opt
@@ -204,7 +205,8 @@
    (watch source opts
      (if-not (nil? env/*compiler*)
        env/*compiler*
-       (env/default-compiler-env opts))))
+       (env/default-compiler-env
+         (closure/add-externs-sources opts)))))
   ([source opts compiler-env]
    (watch source opts compiler-env nil))
   ([source opts compiler-env stop]

src/main/clojure/cljs/closure.clj

@@ -1992,13 +1992,19 @@
 (defn load-data-readers! [compiler]
   (swap! compiler update-in [:cljs.analyzer/data-readers] merge (get-data-readers)))
 
+(defn add-externs-sources [opts]
+  (cond-> opts
+    (:infer-externs opts)
+    (assoc :externs-sources (load-externs (dissoc opts :infer-externs)))))
+
 (defn build
   "Given a source which can be compiled, produce runnable JavaScript."
   ([source opts]
     (build source opts
       (if-not (nil? env/*compiler*)
         env/*compiler*
-        (env/default-compiler-env opts))))
+        (env/default-compiler-env
+          (add-externs-sources opts)))))
   ([source opts compiler-env]
      (env/with-compiler-env compiler-env
        (let [compiler-stats (:compiler-stats opts)

src/main/clojure/cljs/env.cljc

@@ -52,7 +52,7 @@ state that is accessed/maintained by many different components."}
         :cljs.analyzer/constant-table {}
         :cljs.analyzer/data-readers {}
         :cljs.analyzer/externs #?(:clj  (when (:infer-externs options)
-                                          (externs/default-externs))
+                                          (externs/externs-map (:externs-sources options)))
                                   :cljs nil)
         :options options}
        #?(:clj {:js-dependency-index (js-dependency-index options)})))))

src/main/clojure/cljs/externs.clj

@@ -127,39 +127,43 @@
         (seq xs) (update-in xs merge {})))
     {} externs))
 
-(defn default-externs
+(defn externs-map
   ([]
-    (default-externs
-      '{eval {}
-        global {}
-        goog {nodeGlobalRequire {}}
-        COMPILED {}
-        TypeError {}
-        Error {prototype {number {} columnNumber {}}}
-        ReferenceError {}}))
-  ([defaults]
-   (let [xs (CommandLineRunner/getDefaultExterns)]
+   (externs-map (CommandLineRunner/getDefaultExterns)))
+  ([sources]
+   (externs-map sources
+     '{eval {}
+       global {}
+       goog {nodeGlobalRequire {}}
+       COMPILED {}
+       TypeError {}
+       Error {prototype {number {} columnNumber {}}}
+       ReferenceError {}}))
+  ([sources defaults]
+   (let [sources (if-not (empty? sources)
+                   sources
+                   (CommandLineRunner/getDefaultExterns))]
      (reduce
        (fn [externs externs-file]
          (util/map-merge
            externs (index-externs (parse-externs externs-file))))
-       defaults xs))))
+       defaults sources))))
 
 (comment
-  (default-externs)
+  (externs-map)
 
-  (-> (default-externs)
+  (-> (externs-map)
     (find 'console) first meta)
 
-  (get (default-externs) 'Function)
+  (get (externs-map) 'Function)
 
-  (get (default-externs) 'Error)
+  (get (externs-map) 'Error)
 
   ;; values are not on the prototype
-  (get (default-externs) 'Symbol)
-  (get (default-externs) 'Number)
+  (get (externs-map) 'Symbol)
+  (get (externs-map) 'Number)
 
-  (-> (get-in (default-externs) '[Window prototype])
+  (-> (get-in (externs-map) '[Window prototype])
     (find 'performance) first meta)
 
   ;; webkit_dom.js defines Console and Window.prototype.console

src/test/clojure/cljs/analyzer_tests.clj

@@ -621,9 +621,10 @@
 
 (comment
   (require '[cljs.compiler :as cc])
+  (require '[cljs.closure :as closure])
 
   ;; TODO: need to handle the method/fn case
-  (let [test-cenv (atom {::a/externs (externs/default-externs)})]
+  (let [test-cenv (atom {::a/externs (externs/externs-map)})]
     (binding [a/*cljs-ns* a/*cljs-ns*
               a/*cljs-warnings* (assoc a/*cljs-warnings* :infer-warning true)]
       (e/with-compiler-env test-cenv
@@ -641,4 +642,22 @@
           (map (comp :externs second)
             (get @test-cenv ::a/namespaces))))))
 
+  ;; User supplied externs
+  (let [test-cenv (atom {::a/externs (externs/externs-map
+                                       (closure/load-externs
+                                         {:externs ["src/test/externs/test.js"]
+                                          :use-only-custom-externs true}))})]
+    (binding [a/*cljs-ns* a/*cljs-ns*
+              a/*cljs-warnings* (assoc a/*cljs-warnings* :infer-warning true)]
+      (e/with-compiler-env test-cenv
+        (a/analyze-form-seq
+          '[(ns foo.core)
+            (defn bar [^js/Foo a]
+              (.wozMethod a)
+              (.gozMethod a))]))
+      (cc/emit-externs
+        (reduce util/map-merge {}
+          (map (comp :externs second)
+            (get @test-cenv ::a/namespaces))))))
+
   )

src/test/externs/test.js

@@ -0,0 +1,11 @@
+/*
+ @constructor
+ */
+var Foo = function() {};
+Foo.prototype.wozMethod = function() {
+};
+
+/**
+ @return {Foo}
+ */
+baz = function() {};