CLJS-1888 - Seqs of PHMs and PAMs do not handle metadata correctly

Author: thomasmulvaney

src/main/cljs/cljs/core.cljs

@@ -1742,7 +1742,7 @@ reduces them without incurring seq initialization"
     (cons o coll))
 
   IEmptyableCollection
-  (-empty [coll] (-with-meta (.-EMPTY List) meta))
+  (-empty [coll] (.-EMPTY List))
 
   IHash
   (-hash [coll] (hash-ordered-coll coll))
@@ -4874,7 +4874,7 @@ reduces them without incurring seq initialization"
   (-conj [coll o] (cons o coll))
 
   IEmptyableCollection
-  (-empty [coll] (-with-meta (.-EMPTY List) meta))
+  (-empty [coll] (.-EMPTY List))
 
   ISequential
   ISeqable
@@ -4963,7 +4963,7 @@ reduces them without incurring seq initialization"
   (-conj [coll o] (cons o coll))
 
   IEmptyableCollection
-  (-empty [coll] (-with-meta (.-EMPTY List) meta))
+  (-empty [coll] (.-EMPTY List))
 
   IHash
   (-hash [coll] (caching-hash coll hash-ordered-coll __hash))
@@ -5060,7 +5060,7 @@ reduces them without incurring seq initialization"
   (-conj [coll o] (cons o coll))
 
   IEmptyableCollection
-  (-empty [coll] (-with-meta (.-EMPTY List) meta))
+  (-empty [coll] (.-EMPTY List))
 
   ISequential
   ISeqable
@@ -6774,7 +6774,7 @@ reduces them without incurring seq initialization"
     (cons o coll))
 
   IEmptyableCollection
-  (-empty [coll] (-with-meta (.-EMPTY List) _meta))
+  (-empty [coll] (.-EMPTY List))
 
   IHash
   (-hash [coll] (hash-ordered-coll coll))
@@ -6785,13 +6785,13 @@ reduces them without incurring seq initialization"
 
   (-rest [coll]
     (if (< i (- (alength arr) 2))
-      (PersistentArrayMapSeq. arr (+ i 2) _meta)
+      (PersistentArrayMapSeq. arr (+ i 2) nil)
       ()))
 
   INext
   (-next [coll]
     (when (< i (- (alength arr) 2))
-      (PersistentArrayMapSeq. arr (+ i 2) _meta)))
+      (PersistentArrayMapSeq. arr (+ i 2) nil)))
 
   IReduce
   (-reduce [coll f] (seq-reduce f coll))
@@ -7722,7 +7722,7 @@ reduces them without incurring seq initialization"
   (-conj [coll o] (cons o coll))
 
   IEmptyableCollection
-  (-empty [coll] (-with-meta (.-EMPTY List) meta))
+  (-empty [coll] (.-EMPTY List))
 
   ISequential
   ISeq
@@ -7803,18 +7803,18 @@ reduces them without incurring seq initialization"
   (-conj [coll o] (cons o coll))
 
   IEmptyableCollection
-  (-empty [coll] (-with-meta (.-EMPTY List) meta))
+  (-empty [coll] (.-EMPTY List))
 
   ISequential
   ISeq
   (-first [coll] (first s))
   (-rest  [coll]
-    (let [ret (create-array-node-seq nil nodes i (next s))]
+    (let [ret (create-array-node-seq nodes i (next s))]
       (if-not (nil? ret) ret ())))
 
   INext
   (-next [coll]
-    (create-array-node-seq nil nodes i (next s)))
+    (create-array-node-seq nodes i (next s)))
 
   ISeqable
   (-seq [this] this)
@@ -7832,18 +7832,18 @@ reduces them without incurring seq initialization"
 (es6-iterable ArrayNodeSeq)
 
 (defn- create-array-node-seq
-  ([nodes] (create-array-node-seq nil nodes 0 nil))
-  ([meta nodes i s]
+  ([nodes] (create-array-node-seq nodes 0 nil))
+  ([nodes i s]
      (if (nil? s)
        (let [len (alength nodes)]
          (loop [j i]
            (if (< j len)
              (if-let [nj (aget nodes j)]
                (if-let [ns (.inode-seq nj)]
-                 (ArrayNodeSeq. meta nodes (inc j) ns nil)
+                 (ArrayNodeSeq. nil nodes (inc j) ns nil)
                  (recur (inc j)))
                (recur (inc j))))))
-       (ArrayNodeSeq. meta nodes i s nil))))
+       (ArrayNodeSeq. nil nodes i s nil))))
 
 (deftype HashMapIter [nil-val root-iter ^:mutable seen]
   Object
@@ -8972,7 +8972,7 @@ reduces them without incurring seq initialization"
     (cons o coll))
 
   IEmptyableCollection
-  (-empty [coll] (-with-meta (.-EMPTY List) _meta))
+  (-empty [coll] (.-EMPTY List))
 
   IHash
   (-hash [coll] (hash-ordered-coll coll))
@@ -8987,7 +8987,7 @@ reduces them without incurring seq initialization"
                  (-next mseq)
                  (next mseq))]
       (if-not (nil? nseq)
-        (KeySeq. nseq _meta)
+        (KeySeq. nseq nil)
         ())))
 
   INext
@@ -8996,7 +8996,7 @@ reduces them without incurring seq initialization"
                  (-next mseq)
                  (next mseq))]
       (when-not (nil? nseq)
-        (KeySeq. nseq _meta))))
+        (KeySeq. nseq nil))))
 
   IReduce
   (-reduce [coll f] (seq-reduce f coll))
@@ -9724,9 +9724,9 @@ reduces them without incurring seq initialization"
   (-next [rng]
     (if (pos? step)
       (when (< (+ start step) end)
-        (Range. meta (+ start step) end step nil nil nil))
+        (Range. nil (+ start step) end step nil nil nil))
       (when (> (+ start step) end)
-        (Range. meta (+ start step) end step nil nil nil))))
+        (Range. nil (+ start step) end step nil nil nil))))
 
   IChunkedSeq
   (-chunked-first [rng]
@@ -9746,7 +9746,7 @@ reduces them without incurring seq initialization"
   (-conj [rng o] (cons o rng))
 
   IEmptyableCollection
-  (-empty [rng] (-with-meta (.-EMPTY List) meta))
+  (-empty [rng] (-with-meta (.-EMPTY List) nil))
 
   ISequential
   IEquiv

src/test/cljs/cljs/collections_test.cljs

@@ -202,7 +202,7 @@
     (is (= -1 (.lastIndexOf (cycle []) 19 2)))
 
     (is (= {:a 1} (meta (with-meta (cycle [1 2 3]) {:a 1}))))
-    (is (= {:a 1} (meta (empty (with-meta (cycle [1 2 3]) {:a 1})))))
+    (is (nil? (meta (empty (with-meta (cycle [1 2 3]) {:a 1})))))
     (is (= (take 7 (with-meta (cycle [1 2 3]) {:a 1})) (take 7 (cycle [1 2 3]))))
 
     (is (realized? (cycle [1 2 3])))
@@ -291,7 +291,7 @@
     (is (= 3 (.lastIndexOf (repeat 7 5) 5 3)))
 
     (is (= {:a 1} (meta (with-meta (repeat 5 7) {:a 1}))))
-    (is (= {:a 1} (meta (empty (with-meta (repeat 5 7) {:a 1})))))
+    (is (nil? (meta (empty (with-meta (repeat 5 7) {:a 1})))))
     (is (= (with-meta (repeat 5 7) {:a 1}) (repeat 5 7)))
 
     (is (not (realized? (repeat 5 7))))
@@ -338,7 +338,7 @@
     (is (not (realized? (rest (iterate inc 0)))))
 
     (is (= {:a 1} (meta (with-meta (iterate inc 0) {:a 1}))))
-    (is (= {:a 1} (meta (empty (with-meta (iterate inc 0) {:a 1})))))
+    (is (nil? (meta (empty (with-meta (iterate inc 0) {:a 1})))))
     (is (= (take 20 (with-meta (iterate inc 0) {:a 1})) (take 20 (iterate inc 0))))
 
     (is (= [:first 0 1] (take 3 (conj (iterate inc 0) :first))))

src/test/cljs/cljs/hash_map_test.cljs

@@ -97,3 +97,64 @@
       (let [m (array-map nil nil 1 1 2 2)]
         (is (every? map-entry? m))
         (is (every? map-entry? (iter->set (-iterator m))))))))
+
+(deftest test-cljs-1888
+  (let [arr-map-seq (seq (array-map :a 1 :b 2))
+        ;; small hash map will produce a NodeSeq
+        node-seq (seq (hash-map :a 1 :b 2 :c 3))
+        ;; Large hash map will produce an ArrayNodeSeq
+        array-node-seq (seq (into {}
+                                  (map (fn [e] [e nil]))
+                                  (range 1000)))]
+    (testing "PersistentArrayMapSeq"
+      (is (= {:has :meta} (-> arr-map-seq
+                              (with-meta {:has :meta})
+                              (meta))))
+      (is (= nil (-> arr-map-seq
+                     (with-meta {:has :meta})
+                     (rest)
+                     (meta))))
+      (is (= nil (-> arr-map-seq
+                     (with-meta {:has :meta})
+                     (next)
+                     (meta))))
+      (is (= nil (-> arr-map-seq
+                     (with-meta {:has :meta})
+                     (empty)
+                     (meta)))))
+
+    (testing "NodeSeq"
+      (is (instance? NodeSeq node-seq))
+      (is (= {:has :meta} (-> node-seq
+                              (with-meta {:has :meta})
+                              (meta))))
+      (is (= nil (-> node-seq
+                     (with-meta {:has :meta})
+                     (rest)
+                     (meta))))
+      (is (= nil (-> node-seq
+                     (with-meta {:has :meta})
+                     (next)
+                     (meta))))
+      (is (= nil (-> node-seq
+                     (with-meta {:has :meta})
+                     (empty)
+                     (meta)))))
+
+    (testing "ArrayNodeSeq"
+      (is (instance? ArrayNodeSeq array-node-seq))
+      (is (= {:has :meta} (-> array-node-seq
+                              (with-meta {:has :meta})
+                              (meta))))
+      (is (= nil (-> array-node-seq
+                     (with-meta {:has :meta})
+                     (rest)
+                     (meta))))
+      (is (= nil (-> array-node-seq
+                     (with-meta {:has :meta})
+                     (next)
+                     (meta))))
+      (is (= nil (-> array-node-seq
+                     (with-meta {:has :meta})
+                     (empty)
+                     (meta)))))))