Persistence: replace initialState with emptyState (#25129)

akka-cluster-sharding-typed/src/test/scala/akka/cluster/sharding/typed/scaladsl/ClusterShardingPersistenceSpec.scala

@@ -45,7 +45,7 @@ object ClusterShardingPersistenceSpec {
   def persistentActor(entityId: String): Behavior[Command] =
     PersistentBehaviors.receive[Command, String, String](
       entityId,
-      initialState = "",
+      emptyState = "",
       commandHandler = (_, state, cmd) ⇒ cmd match {
         case Add(s) ⇒ Effect.persist(s)
         case Get(replyTo) ⇒

akka-cluster-typed/src/test/scala/akka/cluster/typed/ClusterSingletonPersistenceSpec.scala

@@ -36,7 +36,7 @@ object ClusterSingletonPersistenceSpec {
   val persistentActor: Behavior[Command] =
     PersistentBehaviors.receive[Command, String, String](
       persistenceId = "TheSingleton",
-      initialState = "",
+      emptyState = "",
       commandHandler = (_, state, cmd) ⇒ cmd match {
         case Add(s) ⇒ Effect.persist(s)
         case Get(replyTo) ⇒

akka-docs/src/main/paradox/typed/persistence.md

@@ -42,7 +42,7 @@ The event and state are only used internally.
 The components that make up a PersistentBehavior are:
 
 * `persistenceId` is the unique identifier for the persistent actor.
-* `initialState` defines the `State` when the entity is first created e.g. a Counter would start with 0 as state.
+* `emptyState` defines the `State` when the entity is first created e.g. a Counter would start with 0 as state.
 * `commandHandler` defines how to handle command, resulting in Effects e.g. persisting events, stopping the persistent actor.
 * `eventHandler` updates the current state when an event has been persisted.
 

akka-persistence-typed/src/main/scala/akka/persistence/typed/internal/EventsourcedReplayingSnapshot.scala

@@ -20,7 +20,7 @@ import akka.persistence.typed.internal.EventsourcedBehavior._
  *
  * In this behavior the recovery process is initiated.
  * We try to obtain a snapshot from the configured snapshot store,
- * and if it exists, we use it instead of the `initialState`.
+ * and if it exists, we use it instead of the initial `emptyState`.
  *
  * Once snapshot recovery is done (or no snapshot was selected),
  * recovery of events continues in [[EventsourcedReplayingEvents]].
@@ -96,7 +96,7 @@ private[akka] class EventsourcedReplayingSnapshot[C, E, S](override val setup: E
   def onSnapshotterResponse(response: SnapshotProtocol.Response): Behavior[InternalProtocol] = {
     response match {
       case LoadSnapshotResult(sso, toSnr) ⇒
-        var state: S = setup.initialState
+        var state: S = setup.emptyState
 
         val seqNr: Long = sso match {
           case Some(SelectedSnapshot(metadata, snapshot)) ⇒

akka-persistence-typed/src/main/scala/akka/persistence/typed/internal/EventsourcedSetup.scala

@@ -27,7 +27,7 @@ private[persistence] final class EventsourcedSetup[C, E, S](
   val context:               ActorContext[InternalProtocol],
   val timers:                TimerScheduler[InternalProtocol],
   val persistenceId:         String,
-  val initialState:          S,
+  val emptyState:            S,
   val commandHandler:        PersistentBehaviors.CommandHandler[C, E, S],
   val eventHandler:          (S, E) ⇒ S,
   val writerIdentity:        WriterIdentity,

akka-persistence-typed/src/main/scala/akka/persistence/typed/internal/PersistentBehaviorImpl.scala

@@ -33,7 +33,7 @@ private[akka] object PersistentBehaviorImpl {
 @InternalApi
 private[akka] final case class PersistentBehaviorImpl[Command, Event, State](
   persistenceId:     String,
-  initialState:      State,
+  emptyState:        State,
   commandHandler:    PersistentBehaviors.CommandHandler[Command, Event, State],
   eventHandler:      (State, Event) ⇒ State,
   journalPluginId:   Option[String]                                              = None,
@@ -59,7 +59,7 @@ private[akka] final case class PersistentBehaviorImpl[Command, Event, State](
               ctx,
               timers,
               persistenceId,
-              initialState,
+              emptyState,
               commandHandler,
               eventHandler,
               WriterIdentity.newIdentity(),

akka-persistence-typed/src/main/scala/akka/persistence/typed/javadsl/PersistentBehavior.scala

@@ -29,12 +29,12 @@ abstract class PersistentBehavior[Command, Event, State >: Null](val persistence
   protected final def Effect: EffectFactories[Command, Event, State] = EffectFactory.asInstanceOf[EffectFactories[Command, Event, State]]
 
   /**
-   * Implement by returning the initial state object.
+   * Implement by returning the initial empty state object.
    * This object will be passed into this behaviors handlers, until a new state replaces it.
    *
    * Also known as "zero state" or "neutral state".
    */
-  protected def initialState: State
+  protected def emptyState: State
 
   /**
    * Implement by handling incoming commands and return an `Effect()` to persist or signal other effects
@@ -147,7 +147,7 @@ abstract class PersistentBehavior[Command, Event, State >: Null](val persistence
 
     scaladsl.PersistentBehaviors.receive[Command, Event, State](
       persistenceId,
-      initialState,
+      emptyState,
       (c, state, cmd) ⇒ commandHandler()(c.asJava, state, cmd).asInstanceOf[EffectImpl[Event, State]],
       eventHandler()(_, _))
       .onRecoveryCompleted((ctx, state) ⇒ onRecoveryCompleted(ctx.asJava, state))

akka-persistence-typed/src/main/scala/akka/persistence/typed/scaladsl/PersistentBehaviors.scala

@@ -24,10 +24,10 @@ object PersistentBehaviors {
    */
   def receive[Command, Event, State](
     persistenceId:  String,
-    initialState:   State,
+    emptyState:     State,
     commandHandler: CommandHandler[Command, Event, State],
     eventHandler:   (State, Event) ⇒ State): PersistentBehavior[Command, Event, State] =
-    PersistentBehaviorImpl(persistenceId, initialState, commandHandler, eventHandler)
+    PersistentBehaviorImpl(persistenceId, emptyState, commandHandler, eventHandler)
 
   /**
    * The `CommandHandler` defines how to act on commands.

akka-persistence-typed/src/test/java/akka/persistence/typed/javadsl/PersistentActorCompileOnlyTest.java

@@ -89,7 +89,7 @@ public class PersistentActorCompileOnlyTest {
     //#behavior
     public static PersistentBehavior<SimpleCommand, SimpleEvent, SimpleState> pb = new PersistentBehavior<SimpleCommand, SimpleEvent, SimpleState>("p1") {
       @Override
-      public SimpleState initialState() {
+      public SimpleState emptyState() {
         return new SimpleState();
       }
 
@@ -150,7 +150,7 @@ public class PersistentActorCompileOnlyTest {
 
     private PersistentBehavior<MyCommand, MyEvent, ExampleState> pa = new PersistentBehavior<MyCommand, MyEvent, ExampleState>("pa") {
       @Override
-      public ExampleState initialState() {
+      public ExampleState emptyState() {
         return new ExampleState();
       }
 
@@ -259,7 +259,7 @@ public class PersistentActorCompileOnlyTest {
       }
 
       @Override
-      public EventsInFlight initialState() {
+      public EventsInFlight emptyState() {
         return new EventsInFlight(0, Collections.emptyMap());
       }
 

akka-persistence-typed/src/test/java/akka/persistence/typed/javadsl/PersistentActorJavaDslTest.java

@@ -299,7 +299,7 @@ public class PersistentActorJavaDslTest extends JUnitSuite {
       }
 
       @Override
-      public State initialState() {
+      public State emptyState() {
         return emptyState;
       }
 

akka-persistence-typed/src/test/java/jdocs/akka/persistence/typed/BasicPersistentBehaviorsTest.java

@@ -29,7 +29,7 @@ public class BasicPersistentBehaviorsTest {
     }
 
     @Override
-    public State initialState() {
+    public State emptyState() {
       return new State();
     }
 

akka-persistence-typed/src/test/java/jdocs/akka/persistence/typed/InDepthPersistentBehaviorTest.java

@@ -170,7 +170,7 @@ public class InDepthPersistentBehaviorTest {
     }
 
     @Override
-    public BlogState initialState() {
+    public BlogState emptyState() {
       return new BlogState(Optional.empty(), false);
     }
 

akka-persistence-typed/src/test/scala/akka/persistence/typed/ManyRecoveriesSpec.scala

@@ -29,7 +29,7 @@ object ManyRecoveriesSpec {
     latch: Option[TestLatch]): PersistentBehavior[Cmd, Evt, String] =
     PersistentBehaviors.receive[Cmd, Evt, String](
       persistenceId = name,
-      initialState = "",
+      emptyState = "",
       commandHandler = CommandHandler.command {
         case Cmd(s) ⇒ Effect.persist(Evt(s)).andThen(_ ⇒ probe.ref ! s"$name-$s")
       },

akka-persistence-typed/src/test/scala/akka/persistence/typed/internal/RecoveryPermitterSpec.scala

@@ -44,7 +44,7 @@ object RecoveryPermitterSpec {
     throwOnRecovery: Boolean        = false): Behavior[Command] =
     PersistentBehaviors.receive[Command, Event, State](
       persistenceId = name,
-      initialState = EmptyState,
+      emptyState = EmptyState,
       commandHandler = CommandHandler.command {
         case StopActor ⇒ Effect.stop
         case command   ⇒ commandProbe.ref ! command; Effect.none

akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/OptionalSnapshotStoreSpec.scala

@@ -29,7 +29,7 @@ object OptionalSnapshotStoreSpec {
     name:  String           = UUID.randomUUID().toString) =
     PersistentBehaviors.receive[Command, Event, State](
       persistenceId = name,
-      initialState = State(),
+      emptyState = State(),
       commandHandler = CommandHandler.command {
         _ ⇒ Effect.persist(Event()).andThen(probe.ref ! _)
       },

akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/PersistentActorCompileOnlyTest.scala

@@ -45,7 +45,7 @@ object PersistentActorCompileOnlyTest {
     val simpleBehavior: PersistentBehavior[SimpleCommand, SimpleEvent, ExampleState] =
       PersistentBehaviors.receive[SimpleCommand, SimpleEvent, ExampleState](
         persistenceId = "sample-id-1",
-        initialState = ExampleState(Nil),
+        emptyState = ExampleState(Nil),
         commandHandler = commandHandler,
         eventHandler = eventHandler)
     //#behavior
@@ -66,7 +66,7 @@ object PersistentActorCompileOnlyTest {
     PersistentBehaviors.receive[MyCommand, MyEvent, ExampleState](
       persistenceId = "sample-id-1",
 
-      initialState = ExampleState(Nil),
+      emptyState = ExampleState(Nil),
 
       commandHandler = CommandHandler.command {
         case Cmd(data, sender) ⇒
@@ -110,7 +110,7 @@ object PersistentActorCompileOnlyTest {
     PersistentBehaviors.receive[Command, Event, EventsInFlight](
       persistenceId = "recovery-complete-id",
 
-      initialState = EventsInFlight(0, Map.empty),
+      emptyState = EventsInFlight(0, Map.empty),
 
       commandHandler = (ctx: ActorContext[Command], state, cmd) ⇒ cmd match {
         case DoSideEffect(data) ⇒
@@ -151,7 +151,7 @@ object PersistentActorCompileOnlyTest {
 
     val b: Behavior[Command] = PersistentBehaviors.receive[Command, Event, Mood](
       persistenceId = "myPersistenceId",
-      initialState = Happy,
+      emptyState = Happy,
       commandHandler = CommandHandler.byState {
         case Happy ⇒ CommandHandler.command {
           case Greet(whom) ⇒
@@ -192,7 +192,7 @@ object PersistentActorCompileOnlyTest {
 
     PersistentBehaviors.receive[Command, Event, State](
       persistenceId = "asdf",
-      initialState = State(Nil),
+      emptyState = State(Nil),
       commandHandler = CommandHandler.command {
         case RegisterTask(task) ⇒ Effect.persist(TaskRegistered(task))
         case TaskDone(task)     ⇒ Effect.persist(TaskRemoved(task))
@@ -219,7 +219,7 @@ object PersistentActorCompileOnlyTest {
 
     PersistentBehaviors.receive[Command, Event, State](
       persistenceId = "asdf",
-      initialState = State(Nil),
+      emptyState = State(Nil),
       commandHandler = (ctx, _, cmd) ⇒ cmd match {
         case RegisterTask(task) ⇒
           Effect.persist(TaskRegistered(task))
@@ -282,7 +282,7 @@ object PersistentActorCompileOnlyTest {
 
       PersistentBehaviors.receive[Command, Event, List[Id]](
         persistenceId = "basket-1",
-        initialState = Nil,
+        emptyState = Nil,
         commandHandler =
           CommandHandler.byState(state ⇒
             if (isFullyHydrated(basket, state)) (ctx, state, cmd) ⇒
@@ -343,7 +343,7 @@ object PersistentActorCompileOnlyTest {
 
     PersistentBehaviors.receive[Command, Event, Mood](
       persistenceId = "myPersistenceId",
-      initialState = Sad,
+      emptyState = Sad,
       commandHandler = (_, state, cmd) ⇒
         cmd match {
           case Greet(whom) ⇒
@@ -379,7 +379,7 @@ object PersistentActorCompileOnlyTest {
 
     PersistentBehaviors.receive[Command, Event, State](
       persistenceId = "myPersistenceId",
-      initialState = new State,
+      emptyState = new State,
       commandHandler = CommandHandler.command {
         case Enough ⇒
           Effect.persist(Done)

akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/PersistentBehaviorSpec.scala

@@ -109,7 +109,7 @@ object PersistentBehaviorSpec {
     snapshotProbe: ActorRef[Try[Done]]): PersistentBehavior[Command, Event, State] = {
     PersistentBehaviors.receive[Command, Event, State](
       persistenceId,
-      initialState = State(0, Vector.empty),
+      emptyState = State(0, Vector.empty),
       commandHandler = (ctx, state, cmd) ⇒ cmd match {
         case Increment ⇒
           Effect.persist(Incremented(1))

akka-persistence-typed/src/test/scala/docs/akka/persistence/typed/BasicPersistentBehaviorsCompileOnly.scala

@@ -18,7 +18,7 @@ object BasicPersistentBehaviorsCompileOnly {
   val behavior: Behavior[Command] =
     PersistentBehaviors.receive[Command, Event, State](
       persistenceId = "abc",
-      initialState = State(),
+      emptyState = State(),
       commandHandler = (ctx, state, cmd) ⇒ ???,
       eventHandler = (state, evt) ⇒ ???)
   //#structure
@@ -27,7 +27,7 @@ object BasicPersistentBehaviorsCompileOnly {
   val recoveryBehavior: Behavior[Command] =
     PersistentBehaviors.receive[Command, Event, State](
       persistenceId = "abc",
-      initialState = State(),
+      emptyState = State(),
       commandHandler = (ctx, state, cmd) ⇒ ???,
       eventHandler = (state, evt) ⇒ ???)
       .onRecoveryCompleted { (ctx, state) ⇒
@@ -39,7 +39,7 @@ object BasicPersistentBehaviorsCompileOnly {
   val taggingBehavior: Behavior[Command] =
     PersistentBehaviors.receive[Command, Event, State](
       persistenceId = "abc",
-      initialState = State(),
+      emptyState = State(),
       commandHandler = (ctx, state, cmd) ⇒ ???,
       eventHandler = (state, evt) ⇒ ???
     ).withTagger(_ ⇒ Set("tag1", "tag2"))
@@ -49,7 +49,7 @@ object BasicPersistentBehaviorsCompileOnly {
   //#wrapPersistentBehavior
   val samplePersistentBehavior = PersistentBehaviors.receive[Command, Event, State](
     persistenceId = "abc",
-    initialState = State(),
+    emptyState = State(),
     commandHandler = (ctx, state, cmd) ⇒ ???,
     eventHandler = (state, evt) ⇒ ???)
     .onRecoveryCompleted { (ctx, state) ⇒

akka-persistence-typed/src/test/scala/docs/akka/persistence/typed/InDepthPersistentBehaviorSpec.scala

@@ -121,7 +121,7 @@ object InDepthPersistentBehaviorSpec {
   def behavior(entityId: String): Behavior[BlogCommand] =
     PersistentBehaviors.receive[BlogCommand, BlogEvent, BlogState](
       persistenceId = "Blog-" + entityId,
-      initialState = BlogState.empty,
+      emptyState = BlogState.empty,
       commandHandler,
       eventHandler)
   //#behavior