fix(http2): send ping frames

package.json

@@ -37,17 +37,17 @@
     "watchos"
   ],
   "dependencies": {
-    "fast-jwt": "^5.0.0",
-    "undici": "^7.0.0"
+    "fast-jwt": "^6.0.1",
+    "undici": "^7.9.0"
   },
   "devDependencies": {
     "@biomejs/biome": "^1.9.4",
-    "@tsconfig/node20": "^20.1.4",
-    "@types/node": "^22.10.0",
-    "chai": "^5.1.2",
-    "dotenv": "^16.4.5",
-    "typescript": "^5.7.2",
-    "vitest": "^2.1.6"
+    "@tsconfig/node20": "^20.1.5",
+    "@types/node": "^22.15.19",
+    "chai": "^5.2.0",
+    "dotenv": "^16.5.0",
+    "typescript": "^5.8.3",
+    "vitest": "^3.1.4"
   },
   "scripts": {
     "clean": "rm -rf dist",

src/apns.ts

@@ -2,6 +2,7 @@ import { EventEmitter } from "node:events"
 import { type PrivateKey, createSigner } from "fast-jwt"
 import { type Dispatcher, Pool } from "undici"
 import { ApnsError, type ApnsResponseError, Errors } from "./errors.js"
+import { undici_getClientHttp2Session, undici_getPoolClients } from "./internals.js"
 import { type Notification, Priority } from "./notifications/notification.js"
 
 // APNS version
@@ -13,10 +14,15 @@ const SIGNING_ALGORITHM = "ES256"
 // Reset our signing token every 55 minutes as reccomended by Apple
 const RESET_TOKEN_INTERVAL_MS = 55 * 60 * 1000
 
-export enum Host {
-  production = "api.push.apple.com",
-  development = "api.sandbox.push.apple.com",
-}
+// Ping the server every 10 minutes as reccomended by Apple
+const PING_INTERVAL_MS = 10 * 60 * 1000
+
+export const Host = {
+  production: "api.push.apple.com",
+  development: "api.sandbox.push.apple.com",
+} as const
+
+export type Host = (typeof Host)[keyof typeof Host]
 
 export interface SigningToken {
   value: string
@@ -43,6 +49,7 @@ export class ApnsClient extends EventEmitter {
   readonly client: Pool
 
   private _token: SigningToken | null
+  private _pingInterval: NodeJS.Timeout | null
 
   constructor(options: ApnsOptions) {
     super()
@@ -59,7 +66,9 @@ export class ApnsClient extends EventEmitter {
       maxConcurrentStreams: 100,
     })
     this._token = null
-    this._supressH2Warning()
+    this._pingInterval = this.keepAlive
+      ? setInterval(() => this.ping(), PING_INTERVAL_MS).unref()
+      : null
   }
 
   sendMany(notifications: Notification[]) {
@@ -104,6 +113,35 @@ export class ApnsClient extends EventEmitter {
     return this._handleServerResponse(res, notification)
   }
 
+  async ping() {
+    const sessions = undici_getPoolClients(this.client)
+      .map(undici_getClientHttp2Session)
+      .filter((session) => session !== null)
+      .filter((session) => !session.destroyed && !session.connecting && !session.closed)
+    const promises = sessions.map((session) => {
+      return new Promise<void>((resolve, reject) => {
+        session.ping((err) => (err ? reject(err) : resolve()))
+      })
+    })
+    return Promise.allSettled(promises)
+  }
+
+  async close() {
+    if (this._pingInterval) {
+      clearInterval(this._pingInterval)
+      this._pingInterval = null
+    }
+    await this.client.close()
+  }
+
+  async destroy(err?: Error | null) {
+    if (this._pingInterval) {
+      clearInterval(this._pingInterval)
+      this._pingInterval = null
+    }
+    await this.client.destroy(err ?? null)
+  }
+
   private async _handleServerResponse(res: Dispatcher.ResponseData, notification: Notification) {
     if (res.statusCode === 200) {
       return notification
@@ -157,13 +195,4 @@ export class ApnsClient extends EventEmitter {
 
     return token
   }
-
-  private _supressH2Warning() {
-    process.once("warning", (warning: Error & { code?: string }) => {
-      if (warning.code === "UNDICI-H2") {
-        return
-      }
-      process.emit("warning", warning)
-    })
-  }
 }

src/errors.ts

@@ -1,39 +1,41 @@
 import type { Notification } from "./notifications/notification.js"
 
-export enum Errors {
-  badCertificate = "BadCertificate",
-  badCertificateEnvironment = "BadCertificateEnvironment",
-  badCollapseId = "BadCollapseId",
-  badDeviceToken = "BadDeviceToken",
-  badExpirationDate = "BadExpirationDate",
-  badMessageId = "BadMessageId",
-  badPath = "BadPath",
-  badPriority = "BadPriority",
-  badTopic = "BadTopic",
-  deviceTokenNotForTopic = "DeviceTokenNotForTopic",
-  duplicateHeaders = "DuplicateHeaders",
-  error = "Error",
-  expiredProviderToken = "ExpiredProviderToken",
-  forbidden = "Forbidden",
-  idleTimeout = "IdleTimeout",
-  internalServerError = "InternalServerError",
-  invalidProviderToken = "InvalidProviderToken",
-  invalidPushType = "InvalidPushType",
-  invalidSigningKey = "InvalidSigningKey",
-  methodNotAllowed = "MethodNotAllowed",
-  missingDeviceToken = "MissingDeviceToken",
-  missingProviderToken = "MissingProviderToken",
-  missingTopic = "MissingTopic",
-  payloadEmpty = "PayloadEmpty",
-  payloadTooLarge = "PayloadTooLarge",
-  serviceUnavailable = "ServiceUnavailable",
-  shutdown = "Shutdown",
-  tooManyProviderTokenUpdates = "TooManyProviderTokenUpdates",
-  tooManyRequests = "TooManyRequests",
-  topicDisallowed = "TopicDisallowed",
-  unknownError = "UnknownError",
-  unregistered = "Unregistered",
-}
+export const Errors = {
+  badCertificate: "BadCertificate",
+  badCertificateEnvironment: "BadCertificateEnvironment",
+  badCollapseId: "BadCollapseId",
+  badDeviceToken: "BadDeviceToken",
+  badExpirationDate: "BadExpirationDate",
+  badMessageId: "BadMessageId",
+  badPath: "BadPath",
+  badPriority: "BadPriority",
+  badTopic: "BadTopic",
+  deviceTokenNotForTopic: "DeviceTokenNotForTopic",
+  duplicateHeaders: "DuplicateHeaders",
+  error: "Error",
+  expiredProviderToken: "ExpiredProviderToken",
+  forbidden: "Forbidden",
+  idleTimeout: "IdleTimeout",
+  internalServerError: "InternalServerError",
+  invalidProviderToken: "InvalidProviderToken",
+  invalidPushType: "InvalidPushType",
+  invalidSigningKey: "InvalidSigningKey",
+  methodNotAllowed: "MethodNotAllowed",
+  missingDeviceToken: "MissingDeviceToken",
+  missingProviderToken: "MissingProviderToken",
+  missingTopic: "MissingTopic",
+  payloadEmpty: "PayloadEmpty",
+  payloadTooLarge: "PayloadTooLarge",
+  serviceUnavailable: "ServiceUnavailable",
+  shutdown: "Shutdown",
+  tooManyProviderTokenUpdates: "TooManyProviderTokenUpdates",
+  tooManyRequests: "TooManyRequests",
+  topicDisallowed: "TopicDisallowed",
+  unknownError: "UnknownError",
+  unregistered: "Unregistered",
+} as const
+
+export type Error = (typeof Errors)[keyof typeof Errors]
 
 export interface ApnsResponseError {
   reason: string

src/internals.ts

@@ -0,0 +1,23 @@
+import type { Http2Session } from "node:http2"
+import type { Client } from "undici"
+import type { Pool } from "undici"
+
+export function undici_getPoolClients(pool: Pool): Client[] {
+  const symbols = Object.getOwnPropertySymbols(pool)
+  const clientsSymbol = symbols.find((sym) => sym.description === "clients")
+  if (!clientsSymbol) {
+    return []
+  }
+  // biome-ignore lint/suspicious/noExplicitAny: necessary to access private property
+  return (pool as any)[clientsSymbol] ?? []
+}
+
+export function undici_getClientHttp2Session(client: Client): Http2Session | null {
+  const symbols = Object.getOwnPropertySymbols(client)
+  const http2SessionSymbol = symbols.find((sym) => sym.description === "http2Session")
+  if (!http2SessionSymbol) {
+    return null
+  }
+  // biome-ignore lint/suspicious/noExplicitAny: necessary to access private property
+  return (client as any)[http2SessionSymbol] ?? null
+}

src/notifications/constants/priority.ts

@@ -1,5 +1,7 @@
-export enum Priority {
-  immediate = 10,
-  throttled = 5,
-  low = 1,
-}
+export const Priority = {
+  immediate: 10,
+  throttled: 5,
+  low: 1,
+} as const
+
+export type Priority = (typeof Priority)[keyof typeof Priority]

src/notifications/constants/push-type.ts

@@ -1,11 +1,13 @@
-export enum PushType {
-  alert = "alert",
-  background = "background",
-  voip = "voip",
-  complication = "complication",
-  fileprovider = "fileprovider",
-  mdm = "mdm",
-  liveactivity = "liveactivity",
-  location = "location",
-  pushtotalk = "pushtotalk",
-}
+export const PushType = {
+  alert: "alert",
+  background: "background",
+  voip: "voip",
+  complication: "complication",
+  fileprovider: "fileprovider",
+  mdm: "mdm",
+  liveactivity: "liveactivity",
+  location: "location",
+  pushtotalk: "pushtotalk",
+} as const
+
+export type PushType = (typeof PushType)[keyof typeof PushType]