cljs.metadata-test passing

- Vector uncovered a very old LazySeq bug where it returned meta after
empty. Don't change for now, different path for `:lite-mode`
- Use (.-EMPTY PersistentVector) instead [] for PersistentQueue

Author: swannodette

src/main/cljs/cljs/core.cljs

@@ -3614,7 +3614,13 @@ reduces them without incurring seq initialization"
   (-conj [coll o] (cons o coll))
 
   IEmptyableCollection
-  (-empty [coll] (-with-meta (.-EMPTY List) meta))
+  (-empty [coll]
+    ;; MAYBE FIXME: :lite-mode testing uncovered a very old bug, empty on seq
+    ;; should discared the metadata, we change the behavior in LITE_MODE for now
+    ;; to avoid a breaking change
+    (if-not ^boolean LITE_MODE
+      (-with-meta (.-EMPTY List) meta)
+      (.-EMPTY List)))
 
   ISequential
   IEquiv
@@ -6528,7 +6534,7 @@ reduces them without incurring seq initialization"
   ICounted
   (-count [coll] count))
 
-(set! (.-EMPTY PersistentQueue) (PersistentQueue. nil 0 nil [] empty-ordered-hash))
+(set! (.-EMPTY PersistentQueue) (PersistentQueue. nil 0 nil (.-EMPTY PersistentVector) empty-ordered-hash))
 
 (es6-iterable PersistentQueue)
 

src/test/cljs/cljs/seqs_test.cljs

@@ -40,7 +40,11 @@
       (testing "lazy seq"
         (is (seq? e-lazy-seq))
         (is (empty? e-lazy-seq))
-        (is (= {:b :c} (meta e-lazy-seq)))))
+        ;; MAYBE FIXME: this is a bad test, discovered from :lite-mode work
+        (if-not ^boolean LITE_MODE
+          (is (= {:b :c} (meta e-lazy-seq)))
+          ;; LITE_MODE has the correct behavior
+          (is (nil? (meta e-lazy-seq))))))
     (let [e-list (empty '^{:b :c} (1 2 3))]
       (testing "list"
         (is (seq? e-list))

src/test/cljs/lite_test_runner.cljs

@@ -48,7 +48,7 @@
             [cljs.clojure-alias-test]
             ;; [cljs.hash-map-test]
             ;; [cljs.map-entry-test]
-            ;; [cljs.metadata-test]
+            [cljs.metadata-test]
             [cljs.npm-deps-test]
             [cljs.other-functions-test]
             [cljs.predicates-test]
@@ -107,7 +107,7 @@
   'cljs.specials-test
   'cljs.spec.test-test
   'cljs.clojure-alias-test
-  #_'cljs.metadata-test ;; another RSeq one
+  'cljs.metadata-test
   'cljs.npm-deps-test
   'cljs.other-functions-test
   'cljs.predicates-test