add nextEvents

packages/restate-xstate-test/src/lib/runner.ts

@@ -23,6 +23,8 @@ export type MachineApi = {
   send: (context: unknown, args: { event: AnyEventObject }) => Promise<unknown>;
 
   snapshot: (context: unknown) => Promise<unknown>;
+
+  nextEvents: (context: unknown) => Promise<string[]>;
 };
 
 export type RunMachineOptions = {
@@ -34,6 +36,7 @@ export type RunMachineOptions = {
 export type RunningMachine<SnapshotType> = {
   send: (event: AnyEventObject) => Promise<SnapshotType>;
   snapshot(): Promise<SnapshotType>;
+  nextEvents(): Promise<SnapshotType>;
   [Symbol.dispose](): void;
 };
 
@@ -67,6 +70,10 @@ export async function createRestateTestActor<SnapshotType>(
         return (await client.snapshot()) as SnapshotType;
       },
 
+      nextEvents: async () => {
+        return (await client.nextEvents()) as SnapshotType;
+      },
+
       [Symbol.dispose]: () => {
         env.stop().catch((err: unknown) => {
           console.error("Error stopping environment:", err);

packages/restate-xstate/src/lib/actorObject.ts

@@ -232,6 +232,26 @@ export function actorObject<
 
         return root.getPersistedSnapshot();
       },
+      nextEvents: async (
+        ctx: restate.ObjectContext<State>,
+      ): Promise<string[]> => {
+        await validateStateMachineIsNotDisposed(ctx);
+        const systemName = ctx.key;
+
+        // no need to set the version here if we are just getting a snapshot
+        let version = await ctx.get("version");
+        if (version == null) {
+          version = latestLogic.id;
+        }
+        const logic = getLogic(latestLogic, versions, version);
+
+        const root = await createActor<
+          LatestStateMachine | PreviousStateMachine
+        >(ctx, api, systemName, version, logic);
+
+        const snapshot = root.getSnapshot();
+        return [...new Set([...snapshot._nodes.flatMap((sn) => sn.ownEvents)])];
+      },
       invokePromise: restate.handlers.object.shared(
         async (
           ctx: restate.ObjectSharedContext<State>,

packages/tests/src/lib/example.test.ts

@@ -45,7 +45,8 @@ describe("Simple count machine", () => {
       }>({
         machine: counter,
       });
-
+      const nextEvents = await machine.nextEvents();
+      expect(nextEvents).toStrictEqual(['inc', 'dec'])
       await machine.send({ type: "inc" });
       await machine.send({ type: "inc" });
       await machine.send({ type: "dec" });