polish: clear realtime view data when a debugee ends

Fixes microsoft/vscode#107792

Author: connor4312

packages/vscode-js-profile-flame/src/realtime/chart.ts

@@ -122,6 +122,7 @@ export class Chart {
       return;
     }
 
+    this.hasAnyData = hasData;
     this.elements.container.classList[hasData ? 'remove' : 'add'](styles.noData);
   }
 

packages/vscode-js-profile-flame/src/realtime/client.ts

@@ -34,6 +34,12 @@ window.addEventListener('message', evt => {
       }
       chart.updateMetrics();
       break;
+    case MessageType.ClearData:
+      for (const metric of settings.allMetrics) {
+        metric.setData([]);
+      }
+      chart.updateMetrics();
+      break;
     default:
     // ignored
   }

packages/vscode-js-profile-flame/src/realtime/protocol.ts

@@ -17,6 +17,7 @@ export const enum MessageType {
   SwitchGraph,
   SetEnabledMetrics,
   ApplyData,
+  ClearData,
 }
 
 export interface IDAMetrics {
@@ -90,7 +91,11 @@ export interface IApplyData {
   data: number[][];
 }
 
-export type ToWebViewMessage = IAddData | IUpdateSettingsMessage | IApplyData;
+export interface IClearData {
+  type: MessageType.ClearData;
+}
+
+export type ToWebViewMessage = IAddData | IUpdateSettingsMessage | IApplyData | IClearData;
 export type FromWebViewMessage = ISwitchGraph | ISetEnabledGraphs;
 
 export const getSteps = (settings: ISettings) =>

packages/vscode-js-profile-flame/src/realtimeSessionTracker.ts

@@ -132,13 +132,16 @@ export class RealtimeSessionTracker {
    */
   public onSessionDidEnd(session: vscode.DebugSession) {
     const data = this.sessionData.get(session);
-    if (data) {
-      data.cts.cancel();
-      this.sessionData.delete(session);
+    if (!data) {
+      return;
     }
 
+    data.cts.cancel();
+    this.sessionData.delete(session);
+
     if (this.displayedSession === session) {
       this.displayedSession = undefined;
+      this.broadcast({ type: MessageType.ClearData });
     }
   }