use node-fetch instead of requests (wit-ai#16)

Using the standard fetch API will make it easier to go cross-engine in the future

lib/wit.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const request = require('request');
+const fetch = require('node-fetch');
 const readline = require('readline');
 const uuid = require('node-uuid');
 const Logger = require('./logger').Logger;
@@ -11,29 +11,42 @@ const CALLBACK_TIMEOUT_MS = 10000;
 
 let l = new Logger(logLevels.LOG);
 
-const makeWitResponseHandler = (endpoint, l, cb) => (
-  (error, response, data) => {
-    const err = error ||
-      data.error ||
-      response.statusCode !== 200 && data.body + ' (' + response.statusCode + ')'
-    ;
+const makeWitResponseHandler = (endpoint, l, cb) => {
+  const error = err => {
+    l.error('[' + endpoint + '] Error: ' + err);
+    if (cb) {
+      process.nextTick(() => {
+        cb(err);
+      });
+    }
+  };
+
+  return rsp => {
+    if (rsp instanceof Error) {
+      return error(rsp);
+    }
+
+    const json = rsp[0];
+    const status = rsp[1];
+
+    if (json instanceof Error) {
+      return error(json);
+    }
+
+    const err = json.error || status !== 200 && json.body + ' (' + status + ')';
+
     if (err) {
-      l.error('[' + endpoint + '] Error: ' + err);
-      if (cb) {
-        process.nextTick(() => {
-          cb(err);
-        });
-      }
-      return;
+      return error(err)
     }
-    l.debug('[' + endpoint + '] Response: ' + JSON.stringify(data));
+
+    l.debug('[' + endpoint + '] Response: ' + JSON.stringify(json));
     if (cb) {
       process.nextTick(() => {
-        cb(null, data);
+        cb(null, json);
       });
     }
   }
-);
+};
 
 const validateActions = (actions) => {
   const learnMore = 'Learn more at https://wit.ai/docs/quickstart';
@@ -101,42 +114,52 @@ const clone = (obj) => {
 };
 
 const Wit = function(token, actions, logger) {
-  this.req = request.defaults({
-    baseUrl: process.env.WIT_URL || 'https://api.wit.ai',
-    strictSSL: false,
-    json: true,
-    headers: {
-      'Authorization': 'Bearer ' + token,
-    },
-  });
+  const baseURL = process.env.WIT_URL || 'https://api.wit.ai';
+  const headers = {
+    'Authorization': 'Bearer ' + token,
+    'Accept': 'application/json',
+    'Content-Type': 'application/json',
+  };
   if (logger) {
     l = logger;
   }
   this.actions = validateActions(actions);
 
   this.message = (message, context, cb) => {
-    const options = {
-      uri: '/message',
-      method: 'GET',
-      qs: { q: message },
-    };
+    if (typeof context === 'function') {
+      cb = context;
+      context = undefined;
+    }
+    let qs = 'q=' + encodeURIComponent(message);
     if (context) {
-      options.qs.context = JSON.stringify(context);
+      qs += '&context=' + encodeURIComponent(JSON.stringify(context));
     }
-    this.req(options, makeWitResponseHandler('message', l, cb));
+    const handler = makeWitResponseHandler('message', l, cb);
+    fetch(baseURL + '/message?' + qs, {
+      method: 'GET',
+      headers: headers,
+    })
+    .then(response => Promise.all([response.json(), response.status]))
+    .then(handler)
+    .catch(handler)
+    ;
   };
 
   this.converse = (sessionId, message, context, cb) => {
-    const options = {
-      uri: '/converse',
-      method: 'POST',
-      qs: { 'session_id': sessionId },
-      json: context,
-    };
+    const handler = makeWitResponseHandler('converse', l, cb);
+    let qs = 'session_id=' + sessionId;
     if (message) {
-      options.qs.q = message;
+      qs += '&q=' + encodeURIComponent(message);
     }
-    this.req(options, makeWitResponseHandler('converse', l, cb));
+    fetch(baseURL + '/converse?' + qs, {
+      method: 'POST',
+      headers: headers,
+      body: JSON.stringify(context),
+    })
+    .then(response => Promise.all([response.json(), response.status]))
+    .then(handler)
+    .catch(handler)
+    ;
   };
 
   const makeCallback = (i, sessionId, message, context, cb) => {

package.json

@@ -18,7 +18,7 @@
   "repository": "https://github.com/wit-ai/node-wit",
   "author": "Julien Odent <[email protected]>",
   "dependencies": {
-    "node-uuid": "^1.4.7",
-    "request": "^2.69.0"
+    "node-fetch": "^1.5.1",
+    "node-uuid": "^1.4.7"
   }
 }