From 8254b594598797db621b0a6b260e55941ded7374 Mon Sep 17 00:00:00 2001
From: rozetko <rozetko@hastic.io>
Date: Wed, 24 Jul 2019 16:46:32 +0300
Subject: [PATCH] Error: can't read property 'type' of undefined #353 (#367)

---
 src/panel/graph_panel/graph_ctrl.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/panel/graph_panel/graph_ctrl.ts b/src/panel/graph_panel/graph_ctrl.ts
index abf2910..7ebe975 100644
--- a/src/panel/graph_panel/graph_ctrl.ts
+++ b/src/panel/graph_panel/graph_ctrl.ts
@@ -762,6 +762,9 @@ class GraphCtrl extends MetricsPanelCtrl {
   }
 
   private async _getDatasourceRequest() {
+    if(this._datasourceRequest === undefined) {
+      throw new Error('Datasource is not set. If it`s Grafana test-datasource - it`s not supported');
+    }
     if(this._datasourceRequest.type === undefined) {
       const datasource = await this._getDatasourceByName(this.panel.datasource);
       if(datasource.access !== 'proxy') {