http: add type checking for hostname

Add type checking for options.hostname / options.host
Maintains the use of `undefined` and `null` for default `localhost`,
but other falsy values (like `false`, `0` and `NaN`) are rejected.

PR-URL: https://github.com/nodejs/node/pull/12494
Ref: https://github.com/nodejs/node/issues/12488
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/lib/_http_client.js b/lib/_http_client.js
index 2205e89d2a..42387d0930 100644
--- a/lib/_http_client.js
+++ b/lib/_http_client.js
@@ -65,6 +65,14 @@ function isInvalidPath(s) {
   return false;
 }
 
+function validateHost(host, name) {
+  if (host != null && typeof host !== 'string') {
+    throw new TypeError(
+      `"options.${name}" must either be a string, undefined or null`);
+  }
+  return host;
+}
+
 function ClientRequest(options, cb) {
   OutgoingMessage.call(this);
 
@@ -123,7 +131,8 @@ function ClientRequest(options, cb) {
                       this.agent && this.agent.defaultPort;
 
   var port = options.port = options.port || defaultPort || 80;
-  var host = options.host = options.hostname || options.host || 'localhost';
+  var host = options.host = validateHost(options.hostname, 'hostname') ||
+                            validateHost(options.host, 'host') || 'localhost';
 
   var setHost = (options.setHost === undefined);