Fixed an issue with interpreters started using a persisted state not …

…being "resolved" in full (#3140)

.changeset/hot-trees-occur.md

@@ -0,0 +1,5 @@
+---
+'xstate': patch
+---
+
+Fixed an issue with interpreters started using a persisted state not being "resolved" in full. This could cause some things, such as `after` transitions, not being executed correctly after starting an interpreter like this.

packages/core/src/interpreter.ts

@@ -519,6 +519,12 @@ export class Interpreter<
       return this;
     }
 
+    // yes, it's a hack but we need the related cache to be populated for some things to work (like delayed transitions)
+    // this is usually called by `machine.getInitialState` but if we rehydrate from a state we might bypass this call
+    // we also don't want to call this method here as it resolves the full initial state which might involve calling assign actions
+    // and that could potentially lead to some unwanted side-effects (even such as creating some rogue actors)
+    (this.machine as any)._init();
+
     registry.register(this.sessionId, this as Actor);
     this.initialized = true;
     this.status = InterpreterStatus.Running;

packages/core/test/after.test.ts

@@ -1,4 +1,4 @@
-import { createMachine, interpret } from '../src';
+import { createMachine, interpret, State } from '../src';
 import { after, cancel, send, actionTypes } from '../src/actions';
 import { toSCXMLEvent } from '../src/utils';
 
@@ -170,6 +170,40 @@ describe('delayed transitions', () => {
       .start(machine.getInitialState('withAfter'));
   });
 
+  it('should execute an after transition after starting from a persisted state', (done) => {
+    const createMyMachine = () =>
+      createMachine({
+        initial: 'A',
+        states: {
+          A: {
+            on: {
+              NEXT: 'B'
+            }
+          },
+          B: {
+            after: {
+              1: 'C'
+            }
+          },
+          C: {
+            type: 'final'
+          }
+        }
+      });
+
+    let service = interpret(createMyMachine()).start();
+
+    const persistedState = State.create(
+      JSON.parse(JSON.stringify(service.state))
+    );
+
+    service = interpret(createMyMachine()).start(persistedState);
+
+    service.send({ type: 'NEXT' });
+
+    service.onDone(() => done());
+  });
+
   describe('delay expressions', () => {
     type Events =
       | { type: 'ACTIVATE'; delay: number }