feat: support Keep-Alive Header

node-modules/agentkeepalive#58

.travis.yml

@@ -6,6 +6,7 @@ node_js:
   - '4'
   - '6'
   - '8'
+  - '9'
 script:
   - npm run ci
 after_script:

appveyor.yml

@@ -5,6 +5,7 @@ environment:
     - nodejs_version: '4'
     - nodejs_version: '6'
     - nodejs_version: '8'
+    - nodejs_version: '9'
 
 install:
   - ps: Install-Product node $env:nodejs_version

lib/urllib.js

@@ -56,6 +56,9 @@ var TEXT_DATA_TYPES = [
 
 var PROTO_RE = /^https?:\/\//i;
 
+// Keep-Alive: timeout=5, max=100
+var KEEP_ALIVE_RE = /^timeout=(\d+)/i;
+
 /**
  * Handle all http request, both http and https support well.
  *
@@ -455,6 +458,23 @@ exports.requestWithCallback = function requestWithCallback(url, args, callback)
       err.res = response;
     }
 
+    // only support agentkeepalive module for now
+    if (agent && agent.keepAlive && agent.freeSocketKeepAliveTimeout > 0 &&
+        res.headers.connection === 'keep-alive' && res.headers['keep-alive']) {
+      // adjust freeSocketKeepAliveTimeout on the socket
+      var m = KEEP_ALIVE_RE.exec(res.headers['keep-alive']);
+      if (m) {
+        var seconds = parseInt(m[1]);
+        if (seconds > 0) {
+          // network delay 500ms
+          var serverKeepAliveTimeout = seconds * 1000 - 500;
+          if (serverKeepAliveTimeout < agent.freeSocketKeepAliveTimeout) {
+            res.socket.freeSocketKeepAliveTimeout = serverKeepAliveTimeout;
+          }
+        }
+      }
+    }
+
     cb(err, data, args.streaming ? res : response);
 
     if (args.emitter) {

test/keep-alive-header.test.js

@@ -0,0 +1,55 @@
+'use strict';
+
+var assert = require('assert');
+var http = require('http');
+var Agent = require('agentkeepalive');
+var urllib = require('..');
+
+describe('test/keep-alive-header.test.js', function() {
+  let port;
+  let server;
+  before(function(done) {
+    server = http.createServer(function(req, res) {
+      if (server.keepAliveTimeout) {
+        res.setHeader('Keep-Alive', `timeout=${parseInt(server.keepAliveTimeout / 1000)}`);
+      }
+      res.end('Hello World, ' + req.connection.remotePort);
+    });
+    server.on('clientError', function(err, socket) {
+      socket.end('HTTP/1.1 400 Bad Request\r\n\r\n');
+    });
+    server.keepAliveTimeout = 1000;
+    server.listen(0, function(err) {
+      port = server.address().port;
+      done(err);
+    });
+  });
+
+  it('should handle Keep-Alive header and not throw reset error', function(done) {
+    const keepaliveAgent = new Agent({
+      keepAlive: true,
+    });
+
+    let count = 0;
+    function request() {
+      count++;
+      urllib.request('http://127.0.0.1:' + port + '/foo', {
+        method: 'GET',
+        agent: keepaliveAgent,
+        dataType: 'text',
+      }, function(err, text, res) {
+        assert(!err);
+        assert(res.status === 200);
+        console.log('[%s] status: %s, text: %s, headers: %j', count, text, res.status, res.headers);
+        assert(res.headers.connection === 'keep-alive');
+        assert(res.headers['keep-alive'] === 'timeout=1');
+        if (count > 5) {
+          done();
+        }
+      });
+    }
+
+    setInterval(request, server.keepAliveTimeout);
+    request();
+  });
+});