Add init-fn for datomic component

test demonstrates the ability to init and check for schema

Author: shakdwipeea

project.clj

@@ -20,7 +20,7 @@
                                    [im.chit/hara.io.watch "2.1.7"]
                                    [im.chit/hara.io.scheduler "2.3.6"]
                                    [im.chit/adi "0.3.2"]
-                                   [com.datomic/datomic-free "0.9.4815.12"]
+                                   [com.datomic/datomic-free "0.9.5656"]
                                    [com.novemberain/monger "3.0.2"]
                                    [org.clojure/java.jdbc "0.3.5"]
                                    [com.h2database/h2 "1.4.181"]

src/system/components/datomic.clj

@@ -2,15 +2,19 @@
   (:require [com.stuartsierra.component :as component]
             [datomic.api :as d]))
 
-(defrecord Datomic [uri conn]
+(defrecord Datomic [uri conn init-fn]
   component/Lifecycle
   (start [component]
     (let [db (d/create-database uri)
-          conn (d/connect uri)]
+          conn (d/connect uri)
+          _ (when init-fn (init-fn conn))]
       (assoc component :conn conn)))
   (stop [component]
     (when conn (d/release conn))
     (assoc component :conn nil)))
 
-(defn new-datomic-db [uri]
-  (map->Datomic {:uri uri}))
+(defn new-datomic-db
+  ([uri]
+   (map->Datomic {:uri uri}))
+  ([uri init-fn]
+   (map->Datomic {:uri uri :init-fn init-fn})))

test/system/components/datomic_test.clj

@@ -5,6 +5,7 @@
    [clojure.test :refer [deftest testing is]]))
 
 (def uri "datomic:mem://localhost:4334/framework-test")
+
 (def datomic-db (new-datomic-db uri))
 
 (deftest datomic-lifecycle
@@ -14,3 +15,30 @@
            datomic.peer.LocalConnection))
     (is (d/delete-database uri))
     (alter-var-root #'datomic-db component/stop)))
+
+(def schema '[{:db/ident ::name
+               :db/valueType :db.type/string
+               :db/cardinality :db.cardinality/one
+               :db/doc "a test attr"}])
+
+(defn init-schema [conn]
+  @(d/transact conn schema))
+
+(def datomic-db-with-schema (new-datomic-db uri
+                                            init-schema))
+
+(defn has-attribute?
+  "Does database have an attribute named attr-name?"
+  [db attr-name]
+  (-> (d/entity db attr-name)
+      :db.install/_attribute
+      boolean))
+
+(deftest datomic-lifecycle-with-schema
+  (testing "Datomic lifecycle operations."
+    (alter-var-root #'datomic-db-with-schema component/start)
+    (is (= (type (:conn datomic-db-with-schema))
+           datomic.peer.LocalConnection))
+    (is (has-attribute? (d/db (:conn datomic-db-with-schema)) ::name))
+    (is (d/delete-database uri))
+    (alter-var-root #'datomic-db-with-schema component/stop)))