Raise an error for enablePersistence() in memory-only build

Author: schmidt-sebastian

packages/firestore/src/core/component_provider.ts

@@ -31,7 +31,7 @@ import { Platform } from '../platform/platform';
 import { Datastore } from '../remote/datastore';
 import { User } from '../auth/user';
 import { PersistenceSettings } from './firestore_client';
-import { debugAssert } from '../util/assert';
+import { debugAssert, hardAssert } from '../util/assert';
 import { GarbageCollectionScheduler, Persistence } from '../local/persistence';
 import { Code, FirestoreError } from '../util/error';
 import { OnlineStateSource } from './types';
@@ -133,10 +133,12 @@ export class MemoryComponentProvider implements ComponentProvider {
   }
 
   createPersistence(cfg: ComponentConfiguration): Persistence {
-    debugAssert(
-      !cfg.persistenceSettings.durable,
-      'Can only start memory persistence'
-    );
+    if (cfg.persistenceSettings.durable) {
+      throw new FirestoreError(
+        Code.FAILED_PRECONDITION,
+        MEMORY_ONLY_PERSISTENCE_ERROR_MESSAGE
+      );
+    }
     return new MemoryPersistence(MemoryEagerDelegate.factory);
   }