Fix CLJS tail replay unique conflicts

Author: tiensonqin

src/datascript/storage.cljs

@@ -158,20 +158,25 @@
                       :max-eid max-eid
                       :max-tx  max-tx})]
         (remember-db db)
-        [db (mapv #(keep (fn [[e a v tx]]
-                           ;; TODO: do we still need this?
-                           ;; fix unique constraint
-                           (let [datoms (db/-datoms db :eavt e a v nil)
-                                 datom-exists? (some (fn [datom] (= tx (:tx datom))) datoms)
-                                 ;; retracted tx < 0
-                                 added? (> tx 0)]
-                             (when-not (and datom-exists? added?)
-                               (db/datom e a v tx))))%)
-                  tail)]))))
+        [db (mapv #(mapv (fn [[e a v tx]] (db/datom e a v tx)) %) tail)]))))
+
+(defn- db-with-tail-datoms [db datoms]
+  (try
+    (let [tx  (:tx (first datoms))
+          db' (assoc db :max-tx (dec tx))]
+      (:db-after (db/transact-tx-data (db/->TxReport db' db' [] {} {}) datoms)))
+    (catch :default _
+      db)))
 
 (defn db-with-tail [db tail]
-  ;; Ensures old cardinality/one datoms retracted
-  (:db-after (db/transact-tx-data (db/->TxReport db db [] {} {}) (apply concat tail))))
+  (reduce
+   (fn [db datoms]
+     (if (empty? datoms)
+       db
+       (as-> db %
+         (db-with-tail-datoms % datoms)
+         (assoc % :max-tx (:tx (first datoms))))))
+   db tail))
 
 (defn restore
   ([storage]

test/datascript/test/storage.cljs

@@ -163,7 +163,29 @@
       (d/store db)
       (storage/store-tail db tail)
       (is (= [1772979061145]
-             (mapv :v (d/datoms (d/restore storage) :avet :block/updated-at)))))))
+             (mapv :v (d/datoms (d/restore storage) :avet :block/updated-at))))))
+
+  (testing "restore drops tail groups rejected by unique constraints"
+    (let [schema  {:block/uuid  {:db/unique :db.unique/identity}
+                   :block/title {}}
+          storage (make-storage {:stats true})
+          db      (-> (d/empty-db schema {:storage          storage
+                                          :branching-factor 32
+                                          :ref-type         :strong})
+                      (d/db-with [[:db/add 1 :block/uuid "u1"]]))
+          tail    [[(db/datom 2 :block/uuid "u1" 536870915 true)
+                    (db/datom 2 :block/title "Title" 536870915 true)]
+                   [(db/datom 3 :block/title "Later" 536870916 true)]]]
+      (d/store db)
+      (storage/store-tail db tail)
+      (let [db' (d/restore storage)]
+        (is (= [1]
+               (mapv :e (d/datoms db' :avet :block/uuid "u1"))))
+        (is (= []
+               (mapv (juxt :e :a :v) (d/datoms db' :eavt 2))))
+        (is (= [[3 :block/title "Later"]]
+               (mapv (juxt :e :a :v) (d/datoms db' :eavt 3))))
+        (is (= 536870916 (:max-tx db')))))))
 
 ;; Commented out test-gc test-file-storage tests and helpers b/c they are not implemented in cljs