Add feature: refresh MSTeams token before it expires

__test__/lib/Teams.test.js

@@ -0,0 +1,63 @@
+'use strict';
+let teamsBot;
+let teamsApi;
+let config = {
+    clientId: 'client',
+    clientSecret: 'secret',
+    debug: false
+};
+
+describe('authentication', () => {
+    beforeEach(() => {
+        jest.doMock('../../lib/TeamsAPI', () => {
+            return jest.fn((configuration) => {
+                return {
+                    getToken: jest.fn((cb) => {
+                        configuration.token =  'token';
+                        configuration.token_expires_in = '3600';
+                        cb(null);
+                    })
+                };
+            });
+        });
+
+        jest.useFakeTimers();
+        teamsApi = require('../../lib/TeamsAPI');
+    });
+
+    afterEach(() => {
+        jest.resetModules();
+        jest.clearAllTimers();
+    });
+
+    test('get token', () => {
+        let bot = require('../../lib/Teams')(config);
+        expect(bot.api.getToken).toHaveBeenCalledTimes(1);
+    });
+
+    test('refresh token before expiry', () => {
+        let bot = require('../../lib/Teams')(config);
+        expect(bot.api.getToken).toHaveBeenCalledTimes(1);
+        jest.runOnlyPendingTimers();
+        expect(bot.api.getToken).toHaveBeenCalledTimes(2);
+    });
+
+    test('token valid for 20 mins should refresh after 10 mins', () => {
+        teamsApi.mockImplementation(jest.fn((configuration) => {
+            return {
+                getToken: jest.fn((cb) => {
+                    configuration.token =  'token';
+                    configuration.token_expires_in = '1200';
+                    cb(null);
+                })
+            };
+        }));
+        let bot = require('../../lib/Teams')(config);
+        expect(bot.config.token_expires_in).toBe('1200');
+        expect(bot.api.getToken).toHaveBeenCalledTimes(1);
+        jest.runTimersToTime(1000 * 60 * 9);
+        expect(bot.api.getToken).toHaveBeenCalledTimes(1);
+        jest.runTimersToTime(1000 * 60 * 1.1);
+        expect(bot.api.getToken).toHaveBeenCalledTimes(2);
+    });
+});

lib/Teams.js

@@ -11,14 +11,17 @@ function TeamsBot(configuration) {
     var controller = Botkit(configuration || {});
 
     controller.api = TeamsAPI(configuration || {});
-
-    controller.api.getToken(function(err) {
+    function tokenHandler(err) {
         if (err) {
             // this is a fatal error - could not create a Teams API client
             throw new Error(err);
         }
-    });
-
+        //use the expires_in value, convert to ms and remove 10 mins in ms
+        let tokenExpiresIn = (configuration.token_expires_in || 3600) * 1000;
+        let expiryCheckDelta = 1000 * 60 * 10;
+        setTimeout(controller.api.getToken, (tokenExpiresIn - expiryCheckDelta), tokenHandler);
+    };
+    controller.api.getToken(tokenHandler);
 
     controller.defineBot(function(botkit, config) {
         var bot = {

lib/TeamsAPI.js

@@ -170,6 +170,7 @@ module.exports = function(configuration) {
                         return cb(json.error_description);
                     }
                     configuration.token = json.access_token;
+                    configuration.token_expires_in = json.expires_in;
                     cb(null);
                 }
             }