fix(core): serialize state mutations, fix batch flushing/reentrancy, handle falsy initial values, dispose old StatePart on force, and improve notification/error handling

ts/smartstate.classes.smartstate.ts

@@ -14,6 +14,7 @@ export class Smartstate<StatePartNameType extends string> {
 
   // Batch support
   private batchDepth = 0;
+  private isFlushing = false;
   private pendingNotifications = new Set<StatePart<any, any>>();
 
   constructor() {}
@@ -41,11 +42,18 @@ export class Smartstate<StatePartNameType extends string> {
       await updateFn();
     } finally {
       this.batchDepth--;
-      if (this.batchDepth === 0) {
-        const pending = [...this.pendingNotifications];
-        this.pendingNotifications.clear();
-        for (const sp of pending) {
-          await sp.notifyChange();
+      if (this.batchDepth === 0 && !this.isFlushing) {
+        this.isFlushing = true;
+        try {
+          while (this.pendingNotifications.size > 0) {
+            const pending = [...this.pendingNotifications];
+            this.pendingNotifications.clear();
+            for (const sp of pending) {
+              await sp.notifyChange();
+            }
+          }
+        } finally {
+          this.isFlushing = false;
         }
       }
     }
@@ -84,6 +92,7 @@ export class Smartstate<StatePartNameType extends string> {
             `State part '${statePartNameArg}' already exists, but initMode is 'mandatory'`
           );
         case 'force':
+          existingStatePart.dispose();
           break;
         case 'soft':
         case 'persistent':
@@ -91,7 +100,7 @@ export class Smartstate<StatePartNameType extends string> {
           return existingStatePart as StatePart<StatePartNameType, PayloadType>;
       }
     } else {
-      if (!initialArg) {
+      if (initialArg === undefined) {
         throw new Error(
           `State part '${statePartNameArg}' does not exist and no initial state provided`
         );