Do not throw from d/touch when finding hanging refs

tonsky · Aug 14, 2023 · 3360f74 · 3360f74
1 parent 6c18d23
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,8 @@
+# WIP
+
+- JVM: Return `nil` from `d/restore-conn` if there is no db
+- Do not throw from d/touch when finding hanging refs
+
 # 1.5.2
 
 - JVM: Fixed `d/collect-garbage`

diff --git a/src/datascript/impl/entity.cljc b/src/datascript/impl/entity.cljc
@@ -181,14 +181,15 @@
              not-found)))))))
 
 (defn touch-components [db a->v]
-  (reduce-kv (fn [acc a v]
-               (assoc acc a
-                 (if (db/component? db a)
-                   (if (db/multival? db a)
-                     (set (map touch v))
-                     (touch v))
-                   v)))
-             {} a->v))
+  (reduce-kv
+    (fn [acc a v]
+      (assoc acc a
+        (if (db/component? db a)
+          (if (db/multival? db a)
+            (set (map touch v))
+            (touch v))
+          v)))
+    {} a->v))
 
 (defn- datoms->cache [db datoms]
   (reduce (fn [acc part]
@@ -197,13 +198,14 @@
     {} (partition-by :a datoms)))
 
 (defn touch [^Entity e]
-  {:pre [(entity? e)]}
-  (when-not @(.-touched e)
-    (when-let [datoms (not-empty (db/-search (.-db e) [(.-eid e)]))]
-      (vreset! (.-cache e) (->> datoms
-                                (datoms->cache (.-db e))
-                                (touch-components (.-db e))))
-      (vreset! (.-touched e) true)))
-  e)
+  {:pre [(or (nil? e) (entity? e))]}
+  (when (some? e)
+    (when-not @(.-touched e)
+      (when-let [datoms (not-empty (db/-search (.-db e) [(.-eid e)]))]
+        (vreset! (.-cache e) (->> datoms
+                                  (datoms->cache (.-db e))
+                                  (touch-components (.-db e))))
+        (vreset! (.-touched e) true)))
+    e))
 
 #?(:cljs (goog/exportSymbol "datascript.impl.entity.Entity" Entity))
diff --git a/test/datascript/test/entity.cljc b/test/datascript/test/entity.cljc
@@ -80,6 +80,29 @@
       (is (= (-> (e 100) :_children first :_children) #{(e 1)}))
     )))
 
+(deftest test-missing-refs
+  (let [schema {:ref       {:db/valueType   :db.type/ref}
+                :comp      {:db/valueType   :db.type/ref
+                            :db/isComponent true}
+                :multiref  {:db/valueType   :db.type/ref
+                            :db/cardinality :db.cardinality/many}
+                :multicomp {:db/valueType   :db.type/ref
+                            :db/isComponent true
+                            :db/cardinality :db.cardinality/many}}
+        db     (d/empty-db schema)
+        db'    (d/db-with db
+                 [[:db/add 1 :ref       2]
+                  [:db/add 1 :comp      3]
+                  [:db/add 1 :multiref  4]
+                  [:db/add 1 :multiref  5]
+                  [:db/add 1 :multicomp 6]
+                  [:db/add 1 :multicomp 6]])]
+    (d/touch (d/entity db 1)) ;; does not throw
+    (is (= nil (:ref (d/entity db 1))))
+    (is (= nil (:comp (d/entity db 1))))
+    (is (= nil (:multiref (d/entity db 1))))
+    (is (= nil (:multicomp (d/entity db 1))))))
+
 (deftest test-entity-misses
   (let [db (-> (d/empty-db {:name {:db/unique :db.unique/identity}})
              (d/db-with [{:db/id 1, :name "Ivan"}