Refactor: improved working with promises in testDatasource() method.

src/datasource-zabbix/datasource.js

@@ -8,6 +8,7 @@ import DataProcessor from './DataProcessor';
 import './zabbixAPI.service.js';
 import './zabbixCache.service.js';
 import './queryProcessor.service.js';
+import {ZabbixAPIError} from './zabbixAPICore.service.js';
 
 class ZabbixAPIDatasource {
 
@@ -257,37 +258,33 @@ class ZabbixAPIDatasource {
    * @return {object} Connection status and Zabbix API version
    */
   testDatasource() {
+    let zabbixVersion;
     return this.zabbixAPI.getVersion()
     .then(version => {
-        return this.zabbixAPI.login()
+      zabbixVersion = version;
-          .then(auth => {
+      return this.zabbixAPI.login();
-            if (auth) {
+    })
+    .then(() => {
       return {
         status: "success",
         title: "Success",
-                message: "Zabbix API version: " + version
+        message: "Zabbix API version: " + zabbixVersion
       };
-            } else {
+    })
-              return {
+    .catch(error => {
-                status: "error",
+      if (error instanceof ZabbixAPIError) {
-                title: "Invalid user name or password",
-                message: "Zabbix API version: " + version
-              };
-            }
-          }, error => {
         return {
           status: "error",
           title: error.message,
           message: error.data
         };
-          });
+      } else {
-      }, error => {
-        console.log(error);
         return {
           status: "error",
           title: "Connection failed",
           message: "Could not connect to given url"
         };
+      }
     });
   }