http: add maxTotalSockets to agent class

lib/_http_agent.js

@@ -22,6 +22,7 @@
 'use strict';
 
 const {
+  NumberIsInteger,
   ObjectKeys,
   ObjectSetPrototypeOf,
   ObjectValues,
@@ -99,6 +100,10 @@ function Agent(options) {
 
   if (this.maxTotalSockets !== undefined) {
     validateNumber(this.maxTotalSockets, 'maxTotalSockets');
+    if (!NumberIsInteger(this.maxTotalSockets)) {
+      throw new ERR_OUT_OF_RANGE('maxTotalSockets', 'an integer',
+                                 this.maxTotalSockets);
+    }
     if (this.maxTotalSockets <= 0)
       throw new ERR_OUT_OF_RANGE('maxTotalSockets', '> 0',
                                  this.maxTotalSockets);
@@ -262,7 +267,7 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
     this.sockets[name].push(socket);
     this.totalSocketCount++;
   } else if (sockLen < this.maxSockets &&
-      this.totalSocketCount < this.maxTotalSockets) {
+             this.totalSocketCount < this.maxTotalSockets) {
     debug('call onSocket', sockLen, freeLen);
     // If we are under maxSockets create a new one.
     this.createSocket(req, options, (err, socket) => {

test/parallel/test-http-agent-maxtotalsockets.js

@@ -14,13 +14,26 @@ assert.throws(() => new http.Agent({
     "Received type string ('test')",
 });
 
-assert.throws(() => new http.Agent({
-  maxTotalSockets: -1,
-}), {
-  code: 'ERR_OUT_OF_RANGE',
-  name: 'RangeError',
-  message: 'The value of "maxTotalSockets" is out of range. ' +
-    'It must be > 0. Received -1',
+[NaN, Infinity].forEach((item) => {
+  assert.throws(() => new http.Agent({
+    maxTotalSockets: item,
+  }), {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+    message: 'The value of "maxTotalSockets" is out of range. ' +
+      `It must be an integer. Received ${item}`,
+  });
+});
+
+[-1, 0].forEach((item) => {
+  assert.throws(() => new http.Agent({
+    maxTotalSockets: item,
+  }), {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+    message: 'The value of "maxTotalSockets" is out of range. ' +
+      `It must be > 0. Received ${item}`,
+  });
 });
 
 const maxTotalSockets = 2;
@@ -56,7 +69,7 @@ function handler(s) {
     http.get({
       host: 'localhost',
       port: s.address().port,
-      agent: agent,
+      agent,
       path: `/${i}`,
     }, common.mustCall((res) => {
       assert.strictEqual(res.statusCode, 200);
@@ -91,4 +104,3 @@ function getRequestCount() {
 
 server.listen(0, common.mustCall(() => handler(server)));
 server2.listen(0, common.mustCall(() => handler(server2)));
-