chore: add check for locks

Author: DominicGBauer

packages/web/src/db/PowerSyncDatabase.ts

@@ -28,6 +28,7 @@ import {
   WebStreamingSyncImplementation,
   WebStreamingSyncImplementationOptions
 } from './sync/WebStreamingSyncImplementation';
+import { sdkNavigator } from '../shared/navigator';
 
 export interface WebPowerSyncFlags extends WebSQLFlags {
   /**
@@ -160,7 +161,7 @@ export class PowerSyncDatabase extends AbstractPowerSyncDatabase {
     if (this.resolvedFlags.ssrMode) {
       return PowerSyncDatabase.SHARED_MUTEX.runExclusive(cb);
     }
-    return navigator.locks.request(`lock-${this.database.name}`, cb);
+    return sdkNavigator.locks.request(`lock-${this.database.name}`, cb);
   }
 
   protected generateSyncStreamImplementation(connector: PowerSyncBackendConnector): StreamingSyncImplementation {

packages/web/src/db/adapters/wa-sqlite/WASQLiteDBAdapter.ts

@@ -15,6 +15,7 @@ import type { DBFunctionsInterface, OpenDB } from '../../../shared/types';
 import { _openDB } from '../../../shared/open-db';
 import { getWorkerDatabaseOpener, resolveWorkerDatabasePortFactory } from '../../../worker/db/open-worker-database';
 import { ResolvedWebSQLOpenOptions, resolveWebSQLFlags, WebSQLFlags } from '../web-sql-flags';
+import { sdkNavigator } from '../../../shared/navigator';
 
 /**
  * These flags are the same as {@link WebSQLFlags}.
@@ -186,7 +187,7 @@ export class WASQLiteDBAdapter extends BaseObserver<DBAdapterListener> implement
   }
 
   protected acquireLock(callback: () => Promise<any>): Promise<any> {
-    return navigator.locks.request(`db-lock-${this.options.dbFilename}`, callback);
+    return sdkNavigator.locks.request(`db-lock-${this.options.dbFilename}`, callback);
   }
 
   async readTransaction<T>(fn: (tx: Transaction) => Promise<T>, options?: DBLockOptions | undefined): Promise<T> {

packages/web/src/db/adapters/web-sql-flags.ts

@@ -1,4 +1,5 @@
 import { SQLOpenOptions } from '@powersync/common';
+import { sdkNavigator } from '../../shared/navigator';
 
 /**
  * Common settings used when creating SQL connections on web.
@@ -72,7 +73,7 @@ export const DEFAULT_WEB_SQL_FLAGS: ResolvedWebSQLFlags = {
   enableMultiTabs:
     typeof globalThis.navigator !== 'undefined' && // For SSR purposes
     typeof SharedWorker !== 'undefined' &&
-    !navigator.userAgent.match(/(Android|iPhone|iPod|iPad)/i) &&
+    !sdkNavigator.userAgent.match(/(Android|iPhone|iPod|iPad)/i) &&
     !(window as any).safari,
   useWebWorker: true
 };

packages/web/src/db/sync/WebStreamingSyncImplementation.ts

@@ -5,6 +5,7 @@ import {
   LockType
 } from '@powersync/common';
 import { ResolvedWebSQLOpenOptions, WebSQLFlags } from '../adapters/web-sql-flags';
+import { sdkNavigator } from '../../shared/navigator';
 
 export interface WebStreamingSyncImplementationOptions extends AbstractStreamingSyncImplementationOptions {
   flags?: WebSQLFlags;
@@ -32,6 +33,6 @@ export class WebStreamingSyncImplementation extends AbstractStreamingSyncImpleme
   obtainLock<T>(lockOptions: LockOptions<T>): Promise<T> {
     const identifier = `streaming-sync-${lockOptions.type}-${this.webOptions.identifier}`;
     lockOptions.type == LockType.SYNC && console.debug('requesting lock for ', identifier);
-    return navigator.locks.request(identifier, { signal: lockOptions.signal }, lockOptions.callback);
+    return sdkNavigator.locks.request(identifier, { signal: lockOptions.signal }, lockOptions.callback);
   }
 }

packages/web/src/shared/navigator.ts

@@ -0,0 +1,30 @@
+class SDKNavigator extends Navigator {
+  private static instance: SDKNavigator | null = null;
+
+  constructor() {
+    super();
+    Object.setPrototypeOf(this, SDKNavigator.prototype);
+  }
+
+  public static getInstance(): SDKNavigator {
+    if (!SDKNavigator.instance) {
+      SDKNavigator.instance = new SDKNavigator();
+    }
+    return SDKNavigator.instance;
+  }
+
+  get locks(): LockManager {
+    if (!super.locks) {
+    throw new Error('Navigator locks are not available in this context. ' +
+                    'This may be due to running in an unsecure context. ' +
+                    'Consider using HTTPS or a secure context for full functionality.');
+    }
+    return new Proxy(super.locks, {
+      get(target: LockManager, prop: keyof LockManager) {
+        return target[prop];
+      }
+    });
+  }
+}
+
+export const sdkNavigator = SDKNavigator.getInstance();

packages/web/src/worker/db/WASQLiteDB.worker.ts

@@ -6,6 +6,7 @@ import '@journeyapps/wa-sqlite';
 import * as Comlink from 'comlink';
 import { _openDB } from '../../shared/open-db';
 import type { DBFunctionsInterface } from '../../shared/types';
+import { sdkNavigator } from '../../shared/navigator';
 
 /**
  * Keeps track of open DB connections and the clients which
@@ -23,7 +24,7 @@ let nextClientId = 1;
 
 const openDBShared = async (dbFileName: string): Promise<DBFunctionsInterface> => {
   // Prevent multiple simultaneous opens from causing race conditions
-  return navigator.locks.request(OPEN_DB_LOCK, async () => {
+  return sdkNavigator.locks.request(OPEN_DB_LOCK, async () => {
     const clientId = nextClientId++;
 
     if (!DBMap.has(dbFileName)) {

packages/web/src/worker/sync/SharedSyncImplementation.ts

@@ -23,6 +23,7 @@ import {
 import { WASQLiteDBAdapter } from '../../db/adapters/wa-sqlite/WASQLiteDBAdapter';
 import { AbstractSharedSyncClientProvider } from './AbstractSharedSyncClientProvider';
 import { BroadcastLogger } from './BroadcastLogger';
+import { sdkNavigator } from '../../shared/navigator';
 
 /**
  * Manual message events for shared sync clients
@@ -165,7 +166,7 @@ export class SharedSyncImplementation
   async connect(options?: PowerSyncConnectionOptions) {
     await this.waitForReady();
     // This effectively queues connect and disconnect calls. Ensuring multiple tabs' requests are synchronized
-    return navigator.locks.request('shared-sync-connect', async () => {
+    return sdkNavigator.locks.request('shared-sync-connect', async () => {
       this.syncStreamClient = this.generateStreamingImplementation();
 
       this.syncStreamClient.registerListener({
@@ -181,7 +182,7 @@ export class SharedSyncImplementation
   async disconnect() {
     await this.waitForReady();
     // This effectively queues connect and disconnect calls. Ensuring multiple tabs' requests are synchronized
-    return navigator.locks.request('shared-sync-connect', async () => {
+    return sdkNavigator.locks.request('shared-sync-connect', async () => {
       await this.syncStreamClient?.disconnect();
       await this.syncStreamClient?.dispose();
       this.syncStreamClient = null;

packages/web/tests/shared/navigator.test.ts

@@ -0,0 +1,48 @@
+import { describe, test, expect, beforeEach, vi, afterEach } from 'vitest';
+import { sdkNavigator } from '../../src/shared/navigator';
+
+describe('sdkNavigator', () => {
+  let originalNavigator: Navigator;
+
+  beforeEach(() => {
+    originalNavigator = global.navigator;
+    vi.stubGlobal('navigator', {
+      ...originalNavigator,
+      locks: {
+        request: vi.fn(),
+      },
+    });
+  });
+
+  afterEach(() => {
+    vi.stubGlobal('navigator', originalNavigator);
+  });
+
+  test('should inherit properties from Navigator', () => {
+    expect(sdkNavigator.userAgent).toBe(navigator.userAgent);
+  });
+
+  test('should have locks property', () => {
+    expect(sdkNavigator.locks).toBeDefined();
+    expect(typeof sdkNavigator.locks.request).toBe('function');
+  });
+
+  test('should throw error when locks are not available', () => {
+    vi.stubGlobal('navigator', { ...originalNavigator, locks: undefined });
+    expect(() => sdkNavigator.locks).toThrowError('Navigator locks are not available in this context.');
+  });
+
+  test('locks proxy should pass through method calls when locks are available', () => {
+    const mockCallback = vi.fn();
+    sdkNavigator.locks.request('test', mockCallback);
+    expect(navigator.locks.request).toHaveBeenCalledWith('test', mockCallback);
+  });
+
+  test('should only expose expected Navigator properties', () => {
+    const sdkNavigatorKeys = Object.keys(sdkNavigator);
+    const navigatorKeys = Object.keys(navigator);
+    sdkNavigatorKeys.forEach(key => {
+      expect(navigatorKeys).toContain(key);
+    });
+  });
+});