From 2378c18e6a116b20a33824a15fd82a81b271e9b9 Mon Sep 17 00:00:00 2001
From: Frane Cagalj <fcagalj@gmail.com>
Date: Wed, 15 Mar 2017 00:51:34 +0100
Subject: [PATCH] oauth.token promise, returns token object instead of sending
 response

---
 Readme.md           |  8 ++++++++
 lib/grant.js        | 28 +++++++++++++++++++++++++++-
 lib/oauth2server.js | 24 ++++++++++++++++++++++++
 lib/runner.js       |  4 ++--
 4 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/Readme.md b/Readme.md
index 14db76c43..07a17b0c8 100644
--- a/Readme.md
+++ b/Readme.md
@@ -29,6 +29,14 @@ app.oauth = oauthserver({
 
 app.all('/oauth/token', app.oauth.grant());
 
+app.get('/custom/token', function (req, res) {
+  
+  app.oauth.token(req)
+    .then(function(tokenRes) {
+      res.send(tokenRes);
+    })
+});
+
 app.get('/', app.oauth.authorise(), function (req, res) {
   res.send('Secret area');
 });
diff --git a/lib/grant.js b/lib/grant.js
index 2ebbcd817..ba0c09203 100644
--- a/lib/grant.js
+++ b/lib/grant.js
@@ -46,13 +46,17 @@ var fns = [
  * @param {Object}   res
  * @param {Function} next
  */
-function Grant (config, req, res, next) {
+function Grant(config, req, res, next, returnPromise) {
   this.config = config;
   this.model = config.model;
   this.now = new Date();
   this.req = req;
   this.res = res;
 
+  if (returnPromise) {
+    fns[fns.length - 1] = returnToken;
+  }
+
   runner(fns, this, next);
 }
 
@@ -453,3 +457,25 @@ function sendResponse (done) {
   if (this.config.continueAfterResponse)
     done();
 }
+
+/**
+ * Create an access token and call callback done with token response.
+ *
+ * @param  {Function} done
+ * @this   OAuth
+ */
+function returnToken(done) {
+
+  var response = {
+    token_type: 'bearer',
+    access_token: this.accessToken
+  };
+
+  if (this.config.accessTokenLifetime !== null) {
+    response.expires_in = this.config.accessTokenLifetime;
+  }
+
+  if (this.refreshToken) response.refresh_token = this.refreshToken;
+
+  done(null, response);
+}
\ No newline at end of file
diff --git a/lib/oauth2server.js b/lib/oauth2server.js
index fc6b9c1dc..dd5f3ab03 100644
--- a/lib/oauth2server.js
+++ b/lib/oauth2server.js
@@ -89,6 +89,30 @@ OAuth2Server.prototype.grant = function () {
   };
 };
 
+/**
+ * Token Promise
+ *
+ * Returns promise that will grant tokens to valid requests,
+ * and return object with access token, expire period and token type
+ *
+ * @return {Function} middleware
+ */
+OAuth2Server.prototype.token = function (req) {
+  var self = this;
+
+  return new Promise((resolve, reject) => {
+
+    function cb(err, response) {
+      if(err){
+        return reject(err);
+      }
+      return resolve(response);
+    }
+
+    new Grant(self, req, {}, cb, true);
+  });
+};
+
 /**
  * Code Auth Grant Middleware
  *
diff --git a/lib/runner.js b/lib/runner.js
index 9b25e6213..1212e2e4b 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -12,8 +12,8 @@ function runner (fns, context, next) {
   var last = fns.length - 1;
 
   (function run(pos) {
-    fns[pos].call(context, function (err) {
-      if (err || pos === last) return next(err);
+    fns[pos].call(context, function (err, res) {
+      if (err || pos === last) return next(err, res);
       run(++pos);
     });
   })(0);