From b216489b76ad3e47446729cf52509a55ea30757b Mon Sep 17 00:00:00 2001
From: Anthony Ercolano <anthonyvercolano@outlook.com>
Date: Thu, 25 Oct 2018 12:05:53 -0700
Subject: [PATCH] (fix) Adjust optionality of authentication providers.

---
 common/core/src/authentication_provider.ts    |  3 +-
 .../core/src/sak_authentication_provider.ts   | 37 ++++++++++---------
 .../_device_method_exchange_test.js           |  2 -
 3 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/common/core/src/authentication_provider.ts b/common/core/src/authentication_provider.ts
index 24e4ee599..dea78fa15 100644
--- a/common/core/src/authentication_provider.ts
+++ b/common/core/src/authentication_provider.ts
@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 import { TransportConfig } from './authorization';
+import { Callback } from './promise_utils';
 
 /**
  * Designate the type of authentication used by an `AuthenticationProvider`.
@@ -23,5 +24,5 @@ export enum AuthenticationType {
  */
 export interface AuthenticationProvider {
   type: AuthenticationType;
-  getDeviceCredentials(callback: (err: Error, credentials?: TransportConfig) => void): void;
+  getDeviceCredentials(callback?: Callback<TransportConfig>): Promise<TransportConfig> | void;
 }
diff --git a/device/core/src/sak_authentication_provider.ts b/device/core/src/sak_authentication_provider.ts
index ad8b4f1f2..8ea85d8f3 100644
--- a/device/core/src/sak_authentication_provider.ts
+++ b/device/core/src/sak_authentication_provider.ts
@@ -2,7 +2,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 import { EventEmitter } from 'events';
-import { AuthenticationProvider, AuthenticationType, ConnectionString, SharedAccessSignature, errors, TransportConfig, encodeUriComponentStrict } from 'azure-iot-common';
+import { AuthenticationProvider, AuthenticationType, ConnectionString, SharedAccessSignature, errors, TransportConfig, encodeUriComponentStrict, Callback, callbackToPromise } from 'azure-iot-common';
 
 /**
  * Provides an `AuthenticationProvider` object that can be created simply with a connection string and is then used by the device client and transports to authenticate
@@ -47,23 +47,26 @@ export class SharedAccessKeyAuthenticationProvider extends EventEmitter implemen
   /**
    * This method is used by the transports to gets the most current device credentials in the form of a `TransportConfig` object.
    *
-   * @param callback function that will be called with either an error or a set of device credentials that can be used to authenticate with the IoT hub.
+   * @param [callback] optional function that will be called with either an error or a set of device credentials that can be used to authenticate with the IoT hub.
+   * @returns {Promise<TransportConfig> | void} Promise if no callback function was passed, void otherwise.
    */
-  getDeviceCredentials(callback: (err: Error, credentials?: TransportConfig) => void): void {
-    if (this._shouldRenewToken()) {
-      this._renewToken((err, creds) => {
-        if (err) {
-          callback(err);
-        } else {
-          /*Codes_SRS_NODE_SAK_AUTH_PROVIDER_16_002: [The `getDeviceCredentials` method shall start a timer that will automatically renew the token every (`tokenValidTimeInSeconds` - `tokenRenewalMarginInSeconds`) seconds if specified, or 45 minutes by default.]*/
-          this._scheduleNextExpiryTimeout();
-          callback(null, creds);
-        }
-      });
-    } else {
-      /*Codes_SRS_NODE_SAK_AUTH_PROVIDER_16_003: [The `getDeviceCredentials` should call its callback with a `null` first parameter and a `TransportConfig` object as a second parameter, containing the latest valid token it generated.]*/
-      callback(null, this._credentials);
-    }
+  getDeviceCredentials(callback?: Callback<TransportConfig>): Promise<TransportConfig> | void {
+    return callbackToPromise((_callback) => {
+      if (this._shouldRenewToken()) {
+        this._renewToken((err, creds) => {
+          if (err) {
+            _callback(err);
+          } else {
+            /*Codes_SRS_NODE_SAK_AUTH_PROVIDER_16_002: [The `getDeviceCredentials` method shall start a timer that will automatically renew the token every (`tokenValidTimeInSeconds` - `tokenRenewalMarginInSeconds`) seconds if specified, or 45 minutes by default.]*/
+            this._scheduleNextExpiryTimeout();
+            _callback(null, creds);
+          }
+        });
+      } else {
+        /*Codes_SRS_NODE_SAK_AUTH_PROVIDER_16_003: [The `getDeviceCredentials` should call its callback with a `null` first parameter and a `TransportConfig` object as a second parameter, containing the latest valid token it generated.]*/
+        _callback(null, this._credentials);
+      }
+    }, callback);
   }
 
   /**
diff --git a/device/core/test/device_method/_device_method_exchange_test.js b/device/core/test/device_method/_device_method_exchange_test.js
index 95da087f7..3cbe52c12 100644
--- a/device/core/test/device_method/_device_method_exchange_test.js
+++ b/device/core/test/device_method/_device_method_exchange_test.js
@@ -15,8 +15,6 @@ describe("DeviceMethodRequest", function() {
             const request = new DeviceMethodRequest("requestId", "methodName");
             const response = new DeviceMethodResponse("otherRequestId", {});
             const exchange = createDeviceMethodExchange(request, response);
-
-            console.log(exchange);
             assert.deepEqual(request, exchange.request);
             assert.deepEqual(response, exchange.response);
         });