Add support for http and https proxy (#187)

lib/wit.js

@@ -11,16 +11,32 @@ const {
 } = require('./config');
 const fetch = require('isomorphic-fetch');
 const log = require('./log');
+const Url = require('url');
+const HttpsProxyAgent = require('https-proxy-agent');
 
 const learnMore = 'Learn more at https://wit.ai/docs/quickstart';
 
+function getProxyAgent(witURL) {
+  const url = Url.parse(witURL);
+  const proxy = url.protocol === "http:" ?
+      process.env.http_proxy || process.env.HTTP_PROXY :
+      process.env.https_proxy || process.env.HTTPS_PROXY;
+  const noProxy = process.env.no_proxy || process.env.NO_PROXY;
+
+  const shouldIgnore = noProxy && noProxy.indexOf(url.hostname) > -1;
+  if (proxy && !shouldIgnore) {
+    return new HttpsProxyAgent(proxy);
+  }
+  if(!proxy) return null;
+}
+
 function Wit(opts) {
   if (!(this instanceof Wit)) {
     return new Wit(opts);
   }
 
   const {
-    accessToken, apiVersion, headers, logger, witURL
+    accessToken, apiVersion, headers, logger, witURL, proxy
   } = this.config = Object.freeze(validate(opts));
 
   this._sessions = {};
@@ -46,10 +62,11 @@ function Wit(opts) {
     return fetch(fullURL, {
       method,
       headers,
+      proxy,
     })
-    .then(response => Promise.all([response.json(), response.status]))
-    .then(handler)
-    ;
+        .then(response => Promise.all([response.json(), response.status]))
+        .then(handler)
+        ;
   };
 }
 
@@ -93,6 +110,7 @@ const validate = (opts) => {
     'Content-Type': 'application/json',
   };
   opts.logger = opts.logger || new log.Logger(log.INFO);
+  opts.proxy = getProxyAgent(opts.witURL);
 
   return opts;
 };

package.json

@@ -20,6 +20,7 @@
   "dependencies": {
     "body-parser": "^1.18.2",
     "express": "^4.16.2",
+    "https-proxy-agent": "^1.0.0",
     "isomorphic-fetch": "^2.2.1",
     "request": "^2.83.0",
     "uuid": "^3.0.0"