added waitForReady method

Author: stevensJourney

.changeset/five-turtles-dream.md

@@ -2,5 +2,5 @@
 '@journeyapps/powersync-sdk-common': patch
 ---
 
-- Removed `user-id` header from backend connector and remote headers
-- Mark PowerSync client as pending initialization before `init` has been called.
+- Removed `user-id` header from backend connector and remote headers.
+- Added `waitForReady` method on PowerSyncDatabase client which resolves once initialization is complete.

packages/powersync-sdk-common/src/client/AbstractPowerSyncDatabase.ts

@@ -63,6 +63,7 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
   protected static transactionMutex: Mutex = new Mutex();
 
   closed: boolean;
+  ready: boolean;
 
   currentStatus?: SyncStatus;
   syncStreamImplementation?: AbstractStreamingSyncImplementation;
@@ -71,28 +72,16 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
   private abortController: AbortController | null;
   protected bucketStorageAdapter: BucketStorageAdapter;
   private syncStatusListenerDisposer?: () => void;
-  protected initialized: Promise<void>;
+  protected _isReadyPromise: Promise<void> | null;
 
   constructor(protected options: PowerSyncDatabaseOptions) {
     super();
     this.currentStatus = null;
     this.closed = true;
+    this.ready = false;
     this.options = { ...DEFAULT_POWERSYNC_DB_OPTIONS, ...options };
     this.bucketStorageAdapter = this.generateBucketStorageAdapter();
     this.sdkVersion = '';
-    /**
-     * This will resolve once the DB has been initialized
-     * This allows methods such as `execute` to await initialization before
-     * executing statements
-     */
-    this.initialized = new Promise((resolve) => {
-      const l = this.registerListener({
-        initialized: () => {
-          resolve();
-          l?.();
-        }
-      });
-    });
   }
 
   get schema() {
@@ -113,6 +102,28 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
 
   protected abstract generateBucketStorageAdapter(): BucketStorageAdapter;
 
+  /**
+   * @returns A promise which will resolve once initialization is completed.
+   */
+  async waitForReady(): Promise<void> {
+    if (this.ready) {
+      return;
+    }
+
+    return (
+      this._isReadyPromise ||
+      (this._isReadyPromise = new Promise((resolve) => {
+        const l = this.registerListener({
+          initialized: () => {
+            this.ready = true;
+            resolve();
+            l?.();
+          }
+        });
+      }))
+    );
+  }
+
   abstract _init(): Promise<void>;
 
   /**
@@ -134,7 +145,7 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
     // close connection if one is open
     await this.disconnect();
 
-    await this.initialized;
+    await this.waitForReady();
     this.syncStreamImplementation = this.generateSyncStreamImplementation(connector);
     this.syncStatusListenerDisposer = this.syncStreamImplementation.registerListener({
       statusChanged: (status) => {
@@ -192,7 +203,7 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
    * must be constructed.
    */
   async close() {
-    await this.initialized;
+    await this.waitForReady();
 
     await this.disconnect();
     this.database.close();
@@ -322,31 +333,31 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
    * Execute a statement and optionally return results
    */
   async execute(sql: string, parameters?: any[]) {
-    await this.initialized;
+    await this.waitForReady();
     return this.database.execute(sql, parameters);
   }
 
   /**
    *  Execute a read-only query and return results
    */
   async getAll<T>(sql: string, parameters?: any[]): Promise<T[]> {
-    await this.initialized;
+    await this.waitForReady();
     return this.database.getAll(sql, parameters);
   }
 
   /**
    * Execute a read-only query and return the first result, or null if the ResultSet is empty.
    */
   async getOptional<T>(sql: string, parameters?: any[]): Promise<T | null> {
-    await this.initialized;
+    await this.waitForReady();
     return this.database.getOptional(sql, parameters);
   }
 
   /**
    * Execute a read-only query and return the first result, error if the ResultSet is empty.
    */
   async get<T>(sql: string, parameters?: any[]): Promise<T> {
-    await this.initialized;
+    await this.waitForReady();
     return this.database.get(sql, parameters);
   }
 
@@ -356,7 +367,7 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
    * In most cases, [readTransaction] should be used instead.
    */
   async readLock<T>(callback: (db: DBAdapter) => Promise<T>) {
-    await this.initialized;
+    await this.waitForReady();
     return mutexRunExclusive(AbstractPowerSyncDatabase.transactionMutex, () => callback(this.database));
   }
 
@@ -365,7 +376,7 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
    * In most cases, [writeTransaction] should be used instead.
    */
   async writeLock<T>(callback: (db: DBAdapter) => Promise<T>) {
-    await this.initialized;
+    await this.waitForReady();
     return mutexRunExclusive(AbstractPowerSyncDatabase.transactionMutex, async () => {
       const res = await callback(this.database);
       _.defer(() => this.syncStreamImplementation?.triggerCrudUpload());
@@ -377,7 +388,7 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
     callback: (tx: Transaction) => Promise<T>,
     lockTimeout: number = DEFAULT_LOCK_TIMEOUT_MS
   ): Promise<T> {
-    await this.initialized;
+    await this.waitForReady();
     return this.database.readTransaction(
       async (tx) => {
         const res = await callback({ ...tx });
@@ -392,7 +403,7 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
     callback: (tx: Transaction) => Promise<T>,
     lockTimeout: number = DEFAULT_LOCK_TIMEOUT_MS
   ): Promise<T> {
-    await this.initialized;
+    await this.waitForReady();
     return this.database.writeTransaction(
       async (tx) => {
         const res = await callback(tx);
@@ -478,7 +489,7 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
   }
 
   private async executeReadOnly(sql: string, params: any[]) {
-    await this.initialized;
+    await this.waitForReady();
     return this.database.readLock((tx) => tx.execute(sql, params));
   }
 }

packages/powersync-sdk-react-native/src/db/PowerSyncDatabase.ts

@@ -24,7 +24,7 @@ export class PowerSyncDatabase extends AbstractPowerSyncDatabase {
       adapter: this.bucketStorageAdapter,
       remote,
       uploadCrud: async () => {
-        await this.initialized;
+        await this.waitForReady();
         await connector.uploadData(this);
       },
       retryDelayMs: this.options.retryDelay