Fix subscribeMap EOSE grouping. Fixes #514

* New test for pingpong memory leak (failing).

* Shim once in relay ping mem test.

* Fix pong memory leak with .once.

Fixes #511.

* Fix missing global WebSocket on Node.

* Lint fix.

* Remove overkill WebSocket impl check.

README.md

@@ -133,7 +133,9 @@ import WebSocket from 'ws'
 useWebSocketImplementation(WebSocket)
 ```
 
-You can enable regular pings of connected relays with the `enablePing` option. This will set up a heartbeat that closes the websocket if it doesn't receive a response in time. Some platforms don't report websocket disconnections due to network issues, and enabling this can increase reliability.
+#### enablePing
+
+You can enable regular pings of connected relays with the `enablePing` option. This will set up a heartbeat that closes the websocket if it doesn't receive a response in time. Some platforms, like Node.js, don't report websocket disconnections due to network issues, and enabling this can increase the reliability of the `onclose` event.
 
 ```js
 import { SimplePool } from 'nostr-tools/pool'
@@ -141,6 +143,34 @@ import { SimplePool } from 'nostr-tools/pool'
 const pool = new SimplePool({ enablePing: true })
 ```
 
+#### enableReconnect
+
+You can also enable automatic reconnection with the `enableReconnect` option. This will make the pool try to reconnect to relays with an exponential backoff delay if the connection is lost unexpectedly.
+
+```js
+import { SimplePool } from 'nostr-tools/pool'
+
+const pool = new SimplePool({ enableReconnect: true })
+```
+
+Using both `enablePing: true` and `enableReconnect: true` is recommended as it will improve the reliability and timeliness of the reconnection (at the expense of slighly higher bandwidth due to the ping messages).
+
+```js
+// on Node.js
+const pool = new SimplePool({ enablePing: true, enableReconnect: true })
+```
+
+The `enableReconnect` option can also be a callback function which will receive the current subscription filters and should return a new set of filters. This is useful if you want to modify the subscription on reconnect, for example, to update the `since` parameter to fetch only new events.
+
+```js
+const pool = new SimplePool({
+  enableReconnect: (filters) => {
+    const newSince = Math.floor(Date.now() / 1000)
+    return filters.map(filter => ({ ...filter, since: newSince }))
+  }
+})
+```
+
 ### Parsing references (mentions) from a content based on NIP-27
 
 ```js

abstract-pool.ts

@@ -33,6 +33,7 @@ export class AbstractSimplePool {
 
   public verifyEvent: Nostr['verifyEvent']
   public enablePing: boolean | undefined
+  public enableReconnect: boolean | ((filters: Filter[]) => Filter[]) | undefined
   public trustedRelayURLs: Set<string> = new Set()
 
   private _WebSocket?: typeof WebSocket
@@ -41,6 +42,7 @@ export class AbstractSimplePool {
     this.verifyEvent = opts.verifyEvent
     this._WebSocket = opts.websocketImplementation
     this.enablePing = opts.enablePing
+    this.enableReconnect = opts.enableReconnect
   }
 
   async ensureRelay(url: string, params?: { connectionTimeout?: number }): Promise<AbstractRelay> {
@@ -52,9 +54,12 @@ export class AbstractSimplePool {
         verifyEvent: this.trustedRelayURLs.has(url) ? alwaysTrue : this.verifyEvent,
         websocketImplementation: this._WebSocket,
         enablePing: this.enablePing,
+        enableReconnect: this.enableReconnect,
       })
       relay.onclose = () => {
-        this.relays.delete(url)
+        if (relay && !relay.enableReconnect) {
+          this.relays.delete(url)
+        }
       }
       if (params?.connectionTimeout) relay.connectionTimeout = params.connectionTimeout
       this.relays.set(url, relay)
@@ -131,7 +136,7 @@ export class AbstractSimplePool {
     let handleEose = (i: number) => {
       if (eosesReceived[i]) return // do not act twice for the same relay
       eosesReceived[i] = true
-      if (eosesReceived.filter(a => a).length === requests.length) {
+      if (eosesReceived.filter(a => a).length === groupedRequests.length) {
         params.oneose?.()
         handleEose = () => {}
       }
@@ -142,7 +147,7 @@ export class AbstractSimplePool {
       if (closesReceived[i]) return // do not act twice for the same relay
       handleEose(i)
       closesReceived[i] = reason
-      if (closesReceived.filter(a => a).length === requests.length) {
+      if (closesReceived.filter(a => a).length === groupedRequests.length) {
         params.onclose?.(closesReceived)
         handleClose = () => {}
       }

abstract-relay.ts

@@ -16,6 +16,7 @@ export type AbstractRelayConstructorOptions = {
   verifyEvent: Nostr['verifyEvent']
   websocketImplementation?: typeof WebSocket
   enablePing?: boolean
+  enableReconnect?: boolean | ((filters: Filter[]) => Filter[])
 }
 
 export class SendingOnClosedConnection extends Error {
@@ -37,9 +38,15 @@ export class AbstractRelay {
   public publishTimeout: number = 4400
   public pingFrequency: number = 20000
   public pingTimeout: number = 20000
+  public resubscribeBackoff: number[] = [10000, 10000, 10000, 20000, 20000, 30000, 60000]
   public openSubs: Map<string, Subscription> = new Map()
   public enablePing: boolean | undefined
+  public enableReconnect: boolean | ((filters: Filter[]) => Filter[])
   private connectionTimeoutHandle: ReturnType<typeof setTimeout> | undefined
+  private reconnectTimeoutHandle: ReturnType<typeof setTimeout> | undefined
+  private pingTimeoutHandle: ReturnType<typeof setTimeout> | undefined
+  private reconnectAttempts: number = 0
+  private closedIntentionally: boolean = false
 
   private connectionPromise: Promise<void> | undefined
   private openCountRequests = new Map<string, CountResolver>()
@@ -59,6 +66,7 @@ export class AbstractRelay {
     this.verifyEvent = opts.verifyEvent
     this._WebSocket = opts.websocketImplementation || WebSocket
     this.enablePing = opts.enablePing
+    this.enableReconnect = opts.enableReconnect || false
   }
 
   static async connect(url: string, opts: AbstractRelayConstructorOptions): Promise<AbstractRelay> {
@@ -88,6 +96,40 @@ export class AbstractRelay {
     return this._connected
   }
 
+  private async reconnect(): Promise<void> {
+    const backoff = this.resubscribeBackoff[Math.min(this.reconnectAttempts, this.resubscribeBackoff.length - 1)]
+    this.reconnectAttempts++
+
+    this.reconnectTimeoutHandle = setTimeout(async () => {
+      try {
+        await this.connect()
+      } catch (err) {
+        // this will be called again through onclose/onerror
+      }
+    }, backoff)
+  }
+
+  private handleHardClose(reason: string) {
+    if (this.pingTimeoutHandle) {
+      clearTimeout(this.pingTimeoutHandle)
+      this.pingTimeoutHandle = undefined
+    }
+
+    this._connected = false
+    this.connectionPromise = undefined
+
+    const wasIntentional = this.closedIntentionally
+    this.closedIntentionally = false // reset for next time
+
+    this.onclose?.()
+
+    if (this.enableReconnect && !wasIntentional) {
+      this.reconnect()
+    } else {
+      this.closeAllSubscriptions(reason)
+    }
+  }
+
   public async connect(): Promise<void> {
     if (this.connectionPromise) return this.connectionPromise
 
@@ -110,8 +152,23 @@ export class AbstractRelay {
       }
 
       this.ws.onopen = () => {
+        if (this.reconnectTimeoutHandle) {
+          clearTimeout(this.reconnectTimeoutHandle)
+          this.reconnectTimeoutHandle = undefined
+        }
         clearTimeout(this.connectionTimeoutHandle)
         this._connected = true
+        this.reconnectAttempts = 0
+
+        // resubscribe to all open subscriptions
+        for (const sub of this.openSubs.values()) {
+          sub.eosed = false
+          if (typeof this.enableReconnect === 'function') {
+            sub.filters = this.enableReconnect(sub.filters)
+          }
+          sub.fire()
+        }
+
         if (this.enablePing) {
           this.pingpong()
         }
@@ -121,19 +178,13 @@ export class AbstractRelay {
       this.ws.onerror = ev => {
         clearTimeout(this.connectionTimeoutHandle)
         reject((ev as any).message || 'websocket error')
-        this._connected = false
-        this.connectionPromise = undefined
-        this.onclose?.()
-        this.closeAllSubscriptions('relay connection errored')
+        this.handleHardClose('relay connection errored')
       }
 
       this.ws.onclose = ev => {
         clearTimeout(this.connectionTimeoutHandle)
         reject((ev as any).message || 'websocket closed')
-        this._connected = false
-        this.connectionPromise = undefined
-        this.onclose?.()
-        this.closeAllSubscriptions('relay connection closed')
+        this.handleHardClose('relay connection closed')
       }
 
       this.ws.onmessage = this._onmessage.bind(this)
@@ -142,12 +193,12 @@ export class AbstractRelay {
     return this.connectionPromise
   }
 
-  private async waitForPingPong() {
-    return new Promise((res, err) => {
+  private waitForPingPong() {
+    return new Promise(resolve => {
       // listen for pong
-      ;(this.ws && this.ws.on && this.ws.on('pong', () => res(true))) || err("ws can't listen for pong")
+      ;(this.ws as any).once('pong', () => resolve(true))
       // send a ping
-      this.ws && this.ws.ping && this.ws.ping()
+      this.ws!.ping!()
     })
   }
 
@@ -173,18 +224,17 @@ export class AbstractRelay {
       // wait for either a ping-pong reply or a timeout
       const result = await Promise.any([
         // browsers don't have ping so use a dummy req
-        this.ws && this.ws.ping && this.ws.on ? this.waitForPingPong() : this.waitForDummyReq(),
+        this.ws && this.ws.ping && (this.ws as any).once ? this.waitForPingPong() : this.waitForDummyReq(),
         new Promise(res => setTimeout(() => res(false), this.pingTimeout)),
       ])
       if (result) {
         // schedule another pingpong
-        setTimeout(() => this.pingpong(), this.pingFrequency)
+        this.pingTimeoutHandle = setTimeout(() => this.pingpong(), this.pingFrequency)
       } else {
         // pingpong closing socket
-        this.closeAllSubscriptions('pingpong timed out')
-        this._connected = false
-        this.onclose?.()
-        this.ws?.close()
+        if (this.ws?.readyState === this._WebSocket.OPEN) {
+          this.ws?.close()
+        }
       }
     }
   }
@@ -372,10 +422,21 @@ export class AbstractRelay {
   }
 
   public close() {
+    this.closedIntentionally = true
+    if (this.reconnectTimeoutHandle) {
+      clearTimeout(this.reconnectTimeoutHandle)
+      this.reconnectTimeoutHandle = undefined
+    }
+    if (this.pingTimeoutHandle) {
+      clearTimeout(this.pingTimeoutHandle)
+      this.pingTimeoutHandle = undefined
+    }
     this.closeAllSubscriptions('relay connection closed by us')
     this._connected = false
     this.onclose?.()
-    this.ws?.close()
+    if (this.ws?.readyState === this._WebSocket.OPEN) {
+      this.ws?.close()
+    }
   }
 
   // this is the function assigned to this.ws.onmessage

jsr.json

@@ -1,6 +1,6 @@
 {
   "name": "@nostr/tools",
-  "version": "2.17.0",
+  "version": "2.17.2",
   "exports": {
     ".": "./index.ts",
     "./core": "./core.ts",

nip57.ts

@@ -18,13 +18,13 @@ export async function getZapEndpoint(metadata: Event): Promise<null | string> {
   try {
     let lnurl: string = ''
     let { lud06, lud16 } = JSON.parse(metadata.content)
-    if (lud06) {
+    if (lud16) {
+      let [name, domain] = lud16.split('@')
+      lnurl = new URL(`/.well-known/lnurlp/${name}`, `https://${domain}`).toString()
+    } else if (lud06) {
       let { words } = bech32.decode(lud06, 1000)
       let data = bech32.fromWords(words)
       lnurl = utf8Decoder.decode(data)
-    } else if (lud16) {
-      let [name, domain] = lud16.split('@')
-      lnurl = new URL(`/.well-known/lnurlp/${name}`, `https://${domain}`).toString()
     } else {
       return null
     }

package.json

@@ -1,7 +1,7 @@
 {
   "type": "module",
   "name": "nostr-tools",
-  "version": "2.17.0",
+  "version": "2.17.2",
   "description": "Tools for making a Nostr client.",
   "repository": {
     "type": "git",

pool.test.ts

@@ -59,16 +59,24 @@ test('same with double subs', async () => {
   let priv = generateSecretKey()
   let pub = getPublicKey(priv)
 
-  pool.subscribeMany(relayURLs, { authors: [pub] }, {
-    onevent(event) {
-      received.push(event)
+  pool.subscribeMany(
+    relayURLs,
+    { authors: [pub] },
+    {
+      onevent(event) {
+        received.push(event)
+      },
     },
-  })
-  pool.subscribeMany(relayURLs, { authors: [pub] }, {
-    onevent(event) {
-      received.push(event)
+  )
+  pool.subscribeMany(
+    relayURLs,
+    { authors: [pub] },
+    {
+      onevent(event) {
+        received.push(event)
+      },
     },
-  })
+  )
 
   let received: Event[] = []
 
@@ -172,12 +180,16 @@ test('query a bunch of events and cancel on eose', async () => {
   let events = new Set<string>()
 
   await new Promise<void>(resolve => {
-    pool.subscribeManyEose(relayURLs, { kinds: [0, 1, 2, 3, 4, 5, 6], limit: 40 }, {
-      onevent(event) {
-        events.add(event.id)
+    pool.subscribeManyEose(
+      relayURLs,
+      { kinds: [0, 1, 2, 3, 4, 5, 6], limit: 40 },
+      {
+        onevent(event) {
+          events.add(event.id)
+        },
+        onclose: resolve as any,
       },
-      onclose: resolve as any,
-    })
+    )
   })
 
   expect(events.size).toBeGreaterThan(50)
@@ -210,6 +222,151 @@ test('get()', async () => {
   expect(event).toHaveProperty('id', ids[0])
 })
 
+test('ping-pong timeout in pool', async () => {
+  const mockRelay = mockRelays[0]
+  pool = new SimplePool({ enablePing: true })
+  const relay = await pool.ensureRelay(mockRelay.url)
+  relay.pingTimeout = 50
+  relay.pingFrequency = 50
+
+  let closed = false
+  const closedPromise = new Promise<void>(resolve => {
+    relay.onclose = () => {
+      closed = true
+      resolve()
+    }
+  })
+
+  expect(relay.connected).toBeTrue()
+
+  // wait for the first ping to succeed
+  await new Promise(resolve => setTimeout(resolve, 75))
+  expect(closed).toBeFalse()
+
+  // now make it unresponsive
+  mockRelay.unresponsive = true
+
+  // wait for the second ping to fail
+  await closedPromise
+
+  expect(relay.connected).toBeFalse()
+  expect(closed).toBeTrue()
+})
+
+test('reconnect on disconnect in pool', async () => {
+  const mockRelay = mockRelays[0]
+  pool = new SimplePool({ enablePing: true, enableReconnect: true })
+  const relay = await pool.ensureRelay(mockRelay.url)
+  relay.pingTimeout = 50
+  relay.pingFrequency = 50
+  relay.resubscribeBackoff = [50, 100]
+
+  let closes = 0
+  relay.onclose = () => {
+    closes++
+  }
+
+  expect(relay.connected).toBeTrue()
+
+  // wait for the first ping to succeed
+  await new Promise(resolve => setTimeout(resolve, 75))
+  expect(closes).toBe(0)
+
+  // now make it unresponsive
+  mockRelay.unresponsive = true
+
+  // wait for the second ping to fail, which will trigger a close
+  await new Promise(resolve => {
+    const interval = setInterval(() => {
+      if (closes > 0) {
+        clearInterval(interval)
+        resolve(null)
+      }
+    }, 10)
+  })
+  expect(closes).toBe(1)
+  expect(relay.connected).toBeFalse()
+
+  // now make it responsive again
+  mockRelay.unresponsive = false
+
+  // wait for reconnect
+  await new Promise(resolve => {
+    const interval = setInterval(() => {
+      if (relay.connected) {
+        clearInterval(interval)
+        resolve(null)
+      }
+    }, 10)
+  })
+
+  expect(relay.connected).toBeTrue()
+  expect(closes).toBe(1)
+})
+
+test('reconnect with filter update in pool', async () => {
+  const mockRelay = mockRelays[0]
+  const newSince = Math.floor(Date.now() / 1000)
+  pool = new SimplePool({
+    enablePing: true,
+    enableReconnect: filters => {
+      return filters.map(f => ({ ...f, since: newSince }))
+    },
+  })
+  const relay = await pool.ensureRelay(mockRelay.url)
+  relay.pingTimeout = 50
+  relay.pingFrequency = 50
+  relay.resubscribeBackoff = [50, 100]
+
+  let closes = 0
+  relay.onclose = () => {
+    closes++
+  }
+
+  expect(relay.connected).toBeTrue()
+
+  const sub = relay.subscribe([{ kinds: [1], since: 0 }], { onevent: () => {} })
+  expect(sub.filters[0].since).toBe(0)
+
+  // wait for the first ping to succeed
+  await new Promise(resolve => setTimeout(resolve, 75))
+  expect(closes).toBe(0)
+
+  // now make it unresponsive
+  mockRelay.unresponsive = true
+
+  // wait for the second ping to fail, which will trigger a close
+  await new Promise(resolve => {
+    const interval = setInterval(() => {
+      if (closes > 0) {
+        clearInterval(interval)
+        resolve(null)
+      }
+    }, 10)
+  })
+  expect(closes).toBe(1)
+  expect(relay.connected).toBeFalse()
+
+  // now make it responsive again
+  mockRelay.unresponsive = false
+
+  // wait for reconnect
+  await new Promise(resolve => {
+    const interval = setInterval(() => {
+      if (relay.connected) {
+        clearInterval(interval)
+        resolve(null)
+      }
+    }, 10)
+  })
+
+  expect(relay.connected).toBeTrue()
+  expect(closes).toBe(1)
+
+  // check if filter was updated
+  expect(sub.filters[0].since).toBe(newSince)
+})
+
 test('track relays when publishing', async () => {
   let event1 = finalizeEvent(
     {

pool.ts

@@ -1,7 +1,7 @@
 /* global WebSocket */
 
 import { verifyEvent } from './pure.ts'
-import { AbstractSimplePool } from './abstract-pool.ts'
+import { AbstractSimplePool, type AbstractPoolConstructorOptions } from './abstract-pool.ts'
 
 var _WebSocket: typeof WebSocket
 
@@ -14,7 +14,7 @@ export function useWebSocketImplementation(websocketImplementation: any) {
 }
 
 export class SimplePool extends AbstractSimplePool {
-  constructor(options?: { enablePing?: boolean }) {
+  constructor(options?: Pick<AbstractPoolConstructorOptions, 'enablePing' | 'enableReconnect'>) {
     super({ verifyEvent, websocketImplementation: _WebSocket, ...options })
   }
 }

relay.test.ts

@@ -117,3 +117,285 @@ test('publish timeout', async () => {
     ),
   ).rejects.toThrow('publish timed out')
 })
+
+test('ping-pong timeout (with native ping)', async () => {
+  const mockRelay = new MockRelay()
+  let pingCalled = false
+
+  // mock a native ping/pong mechanism
+  ;(MockWebSocketClient.prototype as any).ping = function (this: any) {
+    pingCalled = true
+    if (!mockRelay.unresponsive) {
+      this.dispatchEvent(new Event('pong'))
+    }
+  }
+  ;(MockWebSocketClient.prototype as any).once = function (
+    this: any,
+    event: string,
+    listener: (...args: any[]) => void,
+  ) {
+    if (event === 'pong') {
+      const onceListener = (...args: any[]) => {
+        this.removeEventListener(event, onceListener)
+        listener.apply(this, args)
+      }
+      this.addEventListener('pong', onceListener)
+    }
+  }
+
+  try {
+    const relay = new Relay(mockRelay.url, { enablePing: true })
+    relay.pingTimeout = 50
+    relay.pingFrequency = 50
+
+    let closed = false
+    const closedPromise = new Promise<void>(resolve => {
+      relay.onclose = () => {
+        closed = true
+        resolve()
+      }
+    })
+
+    await relay.connect()
+    expect(relay.connected).toBeTrue()
+
+    // wait for the first ping to succeed
+    await new Promise(resolve => setTimeout(resolve, 75))
+    expect(pingCalled).toBeTrue()
+    expect(closed).toBeFalse()
+
+    // now make it unresponsive
+    mockRelay.unresponsive = true
+
+    // wait for the second ping to fail
+    await closedPromise
+
+    expect(relay.connected).toBeFalse()
+    expect(closed).toBeTrue()
+  } finally {
+    delete (MockWebSocketClient.prototype as any).ping
+    delete (MockWebSocketClient.prototype as any).once
+  }
+})
+
+test('ping-pong timeout (no-ping browser environment)', async () => {
+  // spy on send to ensure the fallback dummy REQ is used, since MockWebSocketClient has no ping
+  const originalSend = MockWebSocketClient.prototype.send
+  let dummyReqSent = false
+
+  try {
+    MockWebSocketClient.prototype.send = function (message: string) {
+      if (message.includes('REQ') && message.includes('a'.repeat(64))) {
+        dummyReqSent = true
+      }
+      originalSend.call(this, message)
+    }
+
+    const mockRelay = new MockRelay()
+    const relay = new Relay(mockRelay.url, { enablePing: true })
+    relay.pingTimeout = 50
+    relay.pingFrequency = 50
+
+    let closed = false
+    const closedPromise = new Promise<void>(resolve => {
+      relay.onclose = () => {
+        closed = true
+        resolve()
+      }
+    })
+
+    await relay.connect()
+    expect(relay.connected).toBeTrue()
+
+    // wait for the first ping to succeed
+    await new Promise(resolve => setTimeout(resolve, 75))
+    expect(dummyReqSent).toBeTrue()
+    expect(closed).toBeFalse()
+
+    // now make it unresponsive
+    mockRelay.unresponsive = true
+
+    // wait for the second ping to fail
+    await closedPromise
+
+    expect(relay.connected).toBeFalse()
+    expect(closed).toBeTrue()
+  } finally {
+    MockWebSocketClient.prototype.send = originalSend
+  }
+})
+
+test('ping-pong listeners are cleaned up', async () => {
+  const mockRelay = new MockRelay()
+  let listenerCount = 0
+
+  // mock a native ping/pong mechanism
+  ;(MockWebSocketClient.prototype as any).ping = function (this: any) {
+    if (!mockRelay.unresponsive) {
+      this.dispatchEvent(new Event('pong'))
+    }
+  }
+
+  const originalAddEventListener = MockWebSocketClient.prototype.addEventListener
+  MockWebSocketClient.prototype.addEventListener = function (event, listener, options) {
+    if (event === 'pong') {
+      listenerCount++
+    }
+    // @ts-ignore
+    return originalAddEventListener.call(this, event, listener, options)
+  }
+
+  const originalRemoveEventListener = MockWebSocketClient.prototype.removeEventListener
+  MockWebSocketClient.prototype.removeEventListener = function (event, listener) {
+    if (event === 'pong') {
+      listenerCount--
+    }
+    // @ts-ignore
+    return originalRemoveEventListener.call(this, event, listener)
+  }
+
+  // the check in pingpong() is for .once() so we must mock it
+  ;(MockWebSocketClient.prototype as any).once = function (
+    this: any,
+    event: string,
+    listener: (...args: any[]) => void,
+  ) {
+    const onceListener = (...args: any[]) => {
+      this.removeEventListener(event, onceListener)
+      listener.apply(this, args)
+    }
+    this.addEventListener(event, onceListener)
+  }
+
+  try {
+    const relay = new Relay(mockRelay.url, { enablePing: true })
+    relay.pingTimeout = 50
+    relay.pingFrequency = 50
+
+    await relay.connect()
+    await new Promise(resolve => setTimeout(resolve, 175))
+
+    expect(listenerCount).toBeLessThan(2)
+
+    relay.close()
+  } finally {
+    delete (MockWebSocketClient.prototype as any).ping
+    delete (MockWebSocketClient.prototype as any).once
+    MockWebSocketClient.prototype.addEventListener = originalAddEventListener
+    MockWebSocketClient.prototype.removeEventListener = originalRemoveEventListener
+  }
+})
+
+test('reconnect on disconnect', async () => {
+  const mockRelay = new MockRelay()
+  const relay = new Relay(mockRelay.url, { enablePing: true, enableReconnect: true })
+  relay.pingTimeout = 50
+  relay.pingFrequency = 50
+  relay.resubscribeBackoff = [50, 100] // short backoff for testing
+
+  let closes = 0
+  relay.onclose = () => {
+    closes++
+  }
+
+  await relay.connect()
+  expect(relay.connected).toBeTrue()
+
+  // wait for the first ping to succeed
+  await new Promise(resolve => setTimeout(resolve, 75))
+  expect(closes).toBe(0)
+
+  // now make it unresponsive
+  mockRelay.unresponsive = true
+
+  // wait for the second ping to fail, which will trigger a close
+  await new Promise(resolve => {
+    const interval = setInterval(() => {
+      if (closes > 0) {
+        clearInterval(interval)
+        resolve(null)
+      }
+    }, 10)
+  })
+  expect(closes).toBe(1)
+  expect(relay.connected).toBeFalse()
+
+  // now make it responsive again
+  mockRelay.unresponsive = false
+
+  // wait for reconnect
+  await new Promise(resolve => {
+    const interval = setInterval(() => {
+      if (relay.connected) {
+        clearInterval(interval)
+        resolve(null)
+      }
+    }, 10)
+  })
+
+  expect(relay.connected).toBeTrue()
+  expect(closes).toBe(1) // should not have closed again
+})
+
+test('reconnect with filter update', async () => {
+  const mockRelay = new MockRelay()
+  const newSince = Math.floor(Date.now() / 1000)
+  const relay = new Relay(mockRelay.url, {
+    enablePing: true,
+    enableReconnect: filters => {
+      return filters.map(f => ({ ...f, since: newSince }))
+    },
+  })
+  relay.pingTimeout = 50
+  relay.pingFrequency = 50
+  relay.resubscribeBackoff = [50, 100]
+
+  let closes = 0
+  relay.onclose = () => {
+    closes++
+  }
+
+  await relay.connect()
+  expect(relay.connected).toBeTrue()
+
+  const sub = relay.subscribe([{ kinds: [1], since: 0 }], { onevent: () => {} })
+  expect(sub.filters[0].since).toBe(0)
+
+  // wait for the first ping to succeed
+  await new Promise(resolve => setTimeout(resolve, 75))
+  expect(closes).toBe(0)
+
+  // now make it unresponsive
+  mockRelay.unresponsive = true
+
+  // wait for the second ping to fail, which will trigger a close
+  await new Promise(resolve => {
+    const interval = setInterval(() => {
+      if (closes > 0) {
+        clearInterval(interval)
+        resolve(null)
+      }
+    }, 10)
+  })
+  expect(closes).toBe(1)
+  expect(relay.connected).toBeFalse()
+
+  // now make it responsive again
+  mockRelay.unresponsive = false
+
+  // wait for reconnect
+  await new Promise(resolve => {
+    const interval = setInterval(() => {
+      if (relay.connected) {
+        clearInterval(interval)
+        resolve(null)
+      }
+    }, 10)
+  })
+
+  expect(relay.connected).toBeTrue()
+  expect(closes).toBe(1)
+
+  // check if filter was updated
+  expect(sub.filters[0].since).toBe(newSince)
+})

relay.ts

@@ -1,7 +1,7 @@
 /* global WebSocket */
 
 import { verifyEvent } from './pure.ts'
-import { AbstractRelay } from './abstract-relay.ts'
+import { AbstractRelay, type AbstractRelayConstructorOptions } from './abstract-relay.ts'
 
 var _WebSocket: typeof WebSocket
 
@@ -14,12 +14,15 @@ export function useWebSocketImplementation(websocketImplementation: any) {
 }
 
 export class Relay extends AbstractRelay {
-  constructor(url: string) {
-    super(url, { verifyEvent, websocketImplementation: _WebSocket })
+  constructor(url: string, options?: Pick<AbstractRelayConstructorOptions, 'enablePing' | 'enableReconnect'>) {
+    super(url, { verifyEvent, websocketImplementation: _WebSocket, ...options })
   }
 
-  static async connect(url: string): Promise<Relay> {
-    const relay = new Relay(url)
+  static async connect(
+    url: string,
+    options?: Pick<AbstractRelayConstructorOptions, 'enablePing' | 'enableReconnect'>,
+  ): Promise<Relay> {
+    const relay = new Relay(url, options)
     await relay.connect()
     return relay
   }

test-helpers.ts

@@ -26,6 +26,7 @@ export class MockRelay {
   public url: string
   public secretKeys: Uint8Array[]
   public preloadedEvents: Event[]
+  public unresponsive: boolean = false
 
   constructor(url?: string | undefined) {
     serial++
@@ -48,6 +49,7 @@ export class MockRelay {
       let subs: { [subId: string]: { conn: any; filters: Filter[] } } = {}
 
       conn.on('message', (message: string) => {
+        if (this.unresponsive) return
         const data = JSON.parse(message)
 
         switch (data[0]) {