More detailed error messages when available in Android (#323)

* More detailed error messages when available in Android

* More detailed error messages when available in Android

Author: md-waldron

android/src/main/java/com/rnappauth/RNAppAuthModule.java

@@ -187,7 +187,7 @@ public void onFetchConfigurationCompleted(
                                 @Nullable AuthorizationServiceConfiguration fetchedConfiguration,
                                 @Nullable AuthorizationException ex) {
                             if (ex != null) {
-                                promise.reject("Failed to fetch configuration", ex.errorDescription);
+                                promise.reject("Failed to fetch configuration", getErrorMessage(ex));
                                 return;
                             }
 
@@ -269,7 +269,7 @@ public void onFetchConfigurationCompleted(
                                 @Nullable AuthorizationServiceConfiguration fetchedConfiguration,
                                 @Nullable AuthorizationException ex) {
                             if (ex != null) {
-                                promise.reject("Failed to fetch configuration", ex.errorDescription);
+                                promise.reject("Failed to fetch configuration", getErrorMessage(ex));
                                 return;
                             }
 
@@ -303,7 +303,7 @@ public void onActivityResult(Activity activity, int requestCode, int resultCode,
             final AuthorizationResponse response = AuthorizationResponse.fromIntent(data);
             AuthorizationException exception = AuthorizationException.fromIntent(data);
             if (exception != null) {
-                promise.reject("Failed to authenticate", exception.errorDescription);
+                promise.reject("Failed to authenticate", getErrorMessage(exception));
                 return;
             }
 
@@ -325,7 +325,7 @@ public void onTokenRequestCompleted(
                         WritableMap map = TokenResponseFactory.tokenResponseToMap(resp, response);
                         authorizePromise.resolve(map);
                     } else {
-                        promise.reject("Failed exchange token", ex.errorDescription);
+                        promise.reject("Failed exchange token", getErrorMessage(ex));
                     }
                 }
             };
@@ -464,7 +464,7 @@ public void onTokenRequestCompleted(@Nullable TokenResponse response, @Nullable
                     WritableMap map = TokenResponseFactory.tokenResponseToMap(response);
                     promise.resolve(map);
                 } else {
-                    promise.reject("Failed to refresh token", ex.errorDescription);
+                    promise.reject("Failed to refresh token", getErrorMessage(ex));
                 }
             }
         };
@@ -500,6 +500,15 @@ private ClientAuthentication getClientAuthentication(String clientSecret, String
         return new ClientSecretBasic(clientSecret);
     }
 
+    /*
+     * Return error information if it is available
+     */
+    private String getErrorMessage(AuthorizationException ex){
+        if(ex.errorDescription == null && ex.error != null)
+            return ex.error;
+        return ex.errorDescription;
+    }
+
     /*
      * Create a space-delimited string from an array
      */