fix(hulypulse-client): close socket when ping gets no pong

packages/hulypulse-client/src/client.test.ts

@@ -0,0 +1,96 @@
+//
+// Copyright © 2026 Hardcore Engineering Inc.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import { HulypulseClient } from './client'
+
+class FakeWebSocket {
+  static readonly CONNECTING = 0
+  static readonly OPEN = 1
+  static readonly CLOSING = 2
+  static readonly CLOSED = 3
+  static instances: FakeWebSocket[] = []
+
+  readyState = FakeWebSocket.CONNECTING
+  sent: string[] = []
+  closeCode: number | undefined
+  onopen: (() => void) | null = null
+  onclose: ((event: any) => void) | null = null
+  onerror: ((event: any) => void) | null = null
+  onmessage: ((event: any) => void) | null = null
+
+  constructor (readonly url: string) {
+    FakeWebSocket.instances.push(this)
+    setTimeout(() => {
+      this.readyState = FakeWebSocket.OPEN
+      this.onopen?.()
+    }, 0)
+  }
+
+  send (data: string): void {
+    this.sent.push(data)
+  }
+
+  close (code?: number): void {
+    this.closeCode = code
+    this.readyState = FakeWebSocket.CLOSED
+    this.onclose?.({ code })
+  }
+}
+
+describe('HulypulseClient ping', () => {
+  const PING_INTERVAL_MS = 30 * 1000
+  const PING_TIMEOUT_MS = 5 * 60 * 1000
+
+  beforeEach(() => {
+    jest.useFakeTimers()
+    FakeWebSocket.instances = []
+    ;(global as any).WebSocket = FakeWebSocket
+    jest.spyOn(console, 'warn').mockImplementation(() => {})
+  })
+
+  afterEach(() => {
+    jest.useRealTimers()
+    jest.restoreAllMocks()
+  })
+
+  async function connect (): Promise<{ client: HulypulseClient, ws: FakeWebSocket }> {
+    const promise = HulypulseClient.connect('ws://localhost/ws')
+    await jest.advanceTimersByTimeAsync(0)
+    const client = await promise
+    return { client, ws: FakeWebSocket.instances[0] }
+  }
+
+  it('closes an open socket that never answers ping', async () => {
+    const { client, ws } = await connect()
+
+    await jest.advanceTimersByTimeAsync(PING_TIMEOUT_MS + PING_INTERVAL_MS)
+
+    expect(ws.sent).toContain('ping')
+    expect(ws.closeCode).toBe(1000)
+    client.close()
+  })
+
+  it('keeps the socket open while pong replies arrive', async () => {
+    const { client, ws } = await connect()
+
+    for (let i = 0; i < 40; i++) {
+      await jest.advanceTimersByTimeAsync(PING_INTERVAL_MS)
+      ws.onmessage?.({ data: 'pong' })
+    }
+
+    expect(ws.closeCode).toBeUndefined()
+    client.close()
+  })
+})

packages/hulypulse-client/src/client.ts

@@ -227,15 +227,17 @@ export class HulypulseClient implements Disposable {
       if (this.ws?.readyState === WebSocket.OPEN) {
         this.ws.send('ping')
       }
+      // Keep the deadline of the oldest unanswered ping. Resetting it on every
+      // tick would push it back forever, because the interval is shorter than the timeout.
       if (this.pingTimeout !== undefined) {
-        clearTimeout(this.pingTimeout)
+        return
       }
       this.pingTimeout = setTimeout(() => {
-        if (this.ws?.readyState !== WebSocket.OPEN) {
-          console.warn('WS-server not responding to ping, closing connection')
-          clearInterval(this.pingInterval)
-          this.ws?.close(WS_CLOSE_NORMAL)
-        }
+        this.pingTimeout = undefined
+        console.warn('WS-server not responding to ping, closing connection')
+        clearInterval(this.pingInterval)
+        this.pingInterval = undefined
+        this.ws?.close(WS_CLOSE_NORMAL)
       }, this.PING_TIMEOUT_MS)
     }, this.PING_INTERVAL_MS)
   }