Export memfs as well

Author: airhorns

package.json

@@ -36,7 +36,6 @@
     "execa": "^5.1.1",
     "fs-extra": "^11.3.2",
     "lodash": "^4.17.21",
-    "memfs": "^4.49.0",
     "opfs-mock": "^2.4.0",
     "path-browserify": "^1.0.1",
     "playwright": "1.54.1",
@@ -50,6 +49,7 @@
     "yargs": "^17.7.2"
   },
   "dependencies": {
+    "memfs": "^4.49.0",
     "vscode-jsonrpc": "^8.2.1"
   },
   "pnpm": {

pnpm-lock.yaml

@@ -201,8 +201,9 @@ describe("MultiTabWorkerBroker", () => {
       // Teardown the leader
       await broker1.stop();
 
-      // Wait for follower to become leader
-      await new Promise((resolve) => setTimeout(resolve, 100));
+      // Wait for follower to become leader and initialize its worker
+      // Need more time since the worker needs to be created and initialized
+      await new Promise((resolve) => setTimeout(resolve, 150));
       expect(broker2.isLeader).toBe(true);
 
       // Verify new leader can communicate

spec/MultiTabWorkerBroker.spec.ts

@@ -1,7 +1,7 @@
 import { test, describe, beforeEach, afterEach, expect } from "vitest";
 import { vol } from "memfs";
 import "opfs-mock";
-import { MemfsFileSystem } from "./MemFSFileSystem";
+import { MemfsFileSystem } from "../src/MemFSFileSystem";
 import { SyncOPFSFileSystem } from "../src/SyncOPFSFileSystem";
 import { VirtualFileSystem } from "../src/VirtualFileSystem";
 

spec/vfs.spec.ts

@@ -1,6 +1,6 @@
 import { fs, vol } from "memfs";
 import path from "path";
-import { VirtualFileSystem } from "../src/VirtualFileSystem";
+import { VirtualFileSystem } from "./VirtualFileSystem.js";
 
 // Memfs implementation
 export class MemfsFileSystem implements VirtualFileSystem {

spec/MemFSFileSystem.ts src/MemFSFileSystem.tsspec/MemFSFileSystem.ts renamed to src/MemFSFileSystem.ts

@@ -42,6 +42,8 @@ export class MultiTabWorkerBroker {
   private connections = new Map<string, { reader: MultiTabMessageReader; writer: MultiTabMessageWriter }>();
   private nextConnectionId = 0;
   private shouldDebug = false;
+  // Track the active lock request promise to ensure proper cleanup
+  private activeLockPromise: Promise<any> | null = null;
 
   constructor(
     private readonly lockName: string,
@@ -130,8 +132,8 @@ export class MultiTabWorkerBroker {
     // First, try to acquire the lock immediately with ifAvailable
     // This allows us to quickly determine if we can be leader or if another tab already has the lock
     // If we can acquire the lock, we are the leader, and we return promptly from start
-    // Note: not awaited, because this won't ever return if we do acquire the lock as the leader
-    navigator.locks
+    // Store the lock promise so we can wait for it to complete during stop()
+    this.activeLockPromise = navigator.locks
       .request(this.lockName, { ifAvailable: true }, async (lock) => {
         if (lock === null) {
           // Lock is not available - another tab is the leader
@@ -175,8 +177,8 @@ export class MultiTabWorkerBroker {
   private waitForLockAndBecomeLeader(): void {
     // Wait indefinitely to acquire the lock for failover
     // This will block until the current leader releases the lock
-    // Note: not awaited, because this won't ever return if we do acquire the lock and become the leader
-    navigator.locks
+    // Store the lock promise so we can wait for it to complete during stop()
+    this.activeLockPromise = navigator.locks
       .request(this.lockName, { signal: this.lockAbortController!.signal }, async () => {
         // We got the lock! Become the leader and start the worker
         await this.becomeLeader();
@@ -468,6 +470,21 @@ export class MultiTabWorkerBroker {
       this.lockAbortController.abort();
     }
 
+    // Wait for the lock to be fully released before proceeding
+    // This is critical to ensure a new broker can immediately acquire the same lock
+    const lockPromiseToAwait = this.activeLockPromise;
+    if (lockPromiseToAwait) {
+      try {
+        await lockPromiseToAwait;
+      } catch (error) {
+        // Ignore abort errors which are expected during stop
+        if (error && (error as any).name !== "AbortError") {
+          this.error("Error while waiting for lock release:", error);
+        }
+      }
+      this.activeLockPromise = null;
+    }
+
     // Terminate worker if we're the leader
     if (this.worker) {
       this.worker.terminate();

src/MultiTabWorkerBroker.ts

@@ -1,3 +1,4 @@
 export type { VirtualFileSystem } from "./VirtualFileSystem.js";
 export { SyncOPFSFileSystem } from "./SyncOPFSFileSystem.js";
 export { MultiTabWorkerBroker } from "./MultiTabWorkerBroker.js";
+export { MemfsFileSystem } from "./MemFSFileSystem.js";