Optional timeout option for send notification requests (#569)

Fixes #568

Author: carpasse

README.md

@@ -129,6 +129,7 @@ const options = {
     publicKey: '< URL Safe Base64 Encoded Public Key >',
     privateKey: '< URL Safe Base64 Encoded Private Key >'
   },
+  timeout: <Number>
   TTL: <Number>,
   headers: {
     '< header name >': '< header value >'
@@ -179,6 +180,7 @@ any of the following values defined, although none of them are required.
 request only. This overrides any API key set via `setGCMAPIKey()`.
 - **vapidDetails** should be an object with *subject*, *publicKey* and
 *privateKey* values defined. These values should follow the [VAPID Spec](https://tools.ietf.org/html/draft-thomson-webpush-vapid).
+- **timeout** is a value in milliseconds that specifies how long the library must wait for a response from the push service before timing out (by default undefined).
 - **TTL** is a value in seconds that describes how long a push message is
 retained by the push service (by default, four weeks).
 - **headers** is an object with all the extra headers you want to add to the request.

src/web-push-lib.js

@@ -111,6 +111,7 @@ WebPushLib.prototype.generateRequestDetails = function(subscription, payload, op
     let contentEncoding = webPushConstants.supportedContentEncodings.AES_128_GCM;
     let proxy;
     let agent;
+    let timeout;
 
     if (options) {
       const validOptionKeys = [
@@ -120,7 +121,8 @@ WebPushLib.prototype.generateRequestDetails = function(subscription, payload, op
         'TTL',
         'contentEncoding',
         'proxy',
-        'agent'
+        'agent',
+        'timeout'
       ];
       const optionKeys = Object.keys(options);
       for (let i = 0; i < optionKeys.length; i += 1) {
@@ -191,6 +193,10 @@ WebPushLib.prototype.generateRequestDetails = function(subscription, payload, op
           console.warn('Wrong type for the agent option, it should be an instance of https.Agent.');
         }
       }
+
+      if (typeof options.timeout === 'number') {
+        timeout = options.timeout;
+      }
     }
 
     if (typeof timeToLive === 'undefined') {
@@ -277,6 +283,10 @@ WebPushLib.prototype.generateRequestDetails = function(subscription, payload, op
       requestDetails.agent = agent;
     }
 
+    if (timeout) {
+      requestDetails.timeout = timeout;
+    }
+
     return requestDetails;
   };
 
@@ -312,6 +322,10 @@ WebPushLib.prototype.sendNotification = function(subscription, payload, options)
       httpsOptions.headers = requestDetails.headers;
       httpsOptions.method = requestDetails.method;
 
+      if (requestDetails.timeout) {
+        httpsOptions.timeout = requestDetails.timeout;
+      }
+
       if (requestDetails.agent) {
         httpsOptions.agent = requestDetails.agent;
       }