SnapshotStore provides a persistence ID calculation method

Author: Taichi Yamakawa

src/main/scala/lerna/akka/entityreplication/raft/snapshot/SnapshotStore.scala

@@ -17,6 +17,11 @@ private[entityreplication] object SnapshotStore {
       selfMemberIndex: MemberIndex,
   ): Props =
     Props(new SnapshotStore(typeName, entityId, settings, selfMemberIndex))
+
+  /** Returns a persistence ID of SnapshotStore */
+  def persistenceId(typeName: TypeName, entityId: NormalizedEntityId, selfMemberIndex: MemberIndex): String =
+    ActorIds.persistenceId("SnapshotStore", typeName.underlying, entityId.underlying, selfMemberIndex.role)
+
 }
 
 private[entityreplication] class SnapshotStore(

src/test/scala/lerna/akka/entityreplication/raft/snapshot/SnapshotStoreSpec.scala

@@ -0,0 +1,24 @@
+package lerna.akka.entityreplication.raft.snapshot
+
+import akka.actor.ActorSystem
+import akka.testkit.TestKit
+import lerna.akka.entityreplication.model.{ NormalizedEntityId, TypeName }
+import lerna.akka.entityreplication.raft.ActorSpec
+import lerna.akka.entityreplication.raft.routing.MemberIndex
+
+final class SnapshotStoreSpec extends TestKit(ActorSystem("SnapshotStoreSpec")) with ActorSpec {
+
+  "SnapshotStore.persistenceId" should {
+
+    "return a persistence ID for the given type name, entity ID, and member index" in {
+      val persistenceId = SnapshotStore.persistenceId(
+        TypeName.from("test-type-name"),
+        NormalizedEntityId.from("test-entity-id"),
+        MemberIndex("test-member-index"),
+      )
+      assert(persistenceId === "SnapshotStore:test-type-name:test-entity-id:test-member-index")
+    }
+
+  }
+
+}