Show detailed deployment error message, and minor fix (#26)

src/iotEdgeExplorer.ts

@@ -145,6 +145,9 @@ export class IoTEdgeExplorer extends BaseExplorer {
             })
             .catch((err) => {
                 this.outputLine(label, `Deployment failed. ${err}`);
+                if (err && err.response && err.response.data && err.response.data.Message) {
+                    this.outputLine(label, err.response.data.Message);
+                }
                 TelemetryClient.sendEvent(Constants.IoTHubAIEdgeDeployDoneEvent, { Result: "Fail", Message: err });
             });
     }

src/iotHubC2DMessageExplorer.ts

@@ -43,7 +43,7 @@ export class IotHubC2DMessageExplorer extends BaseExplorer {
             return;
         }
 
-        let deviceConnectionString = deviceItem.connectionString ?
+        let deviceConnectionString = (deviceItem && deviceItem.connectionString) ?
             deviceItem.connectionString : await Utility.getConnectionString(Constants.DeviceConnectionStringKey,
                 Constants.DeviceConnectionStringTitle);
         if (!deviceConnectionString) {

src/iotHubMessageExplorer.ts

@@ -17,7 +17,7 @@ export class IoTHubMessageExplorer extends BaseExplorer {
     }
 
     public async sendD2CMessage(deviceItem?: DeviceItem) {
-        let deviceConnectionString = deviceItem.connectionString ?
+        let deviceConnectionString = (deviceItem && deviceItem.connectionString) ?
             deviceItem.connectionString : await Utility.getConnectionString(Constants.DeviceConnectionStringKey,
                 Constants.DeviceConnectionStringTitle);
         if (!deviceConnectionString) {