Show something useful when there are no notifications in the notifications view (#6896)

Fixes #6856

Author: alexr00

package.json

@@ -1696,7 +1696,7 @@
 			},
 			{
 				"view": "notifications:github",
-				"when": "ReposManagerStateContext == RepositoriesLoaded && github:notificationCount == 0",
+				"when": "ReposManagerStateContext == RepositoriesLoaded && github:notificationCount == -1",
 				"contents": "%welcome.github.notifications.contents%"
 			}
 		],

src/notifications/notificationsManager.ts

@@ -4,6 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as vscode from 'vscode';
+import { commands, contexts } from '../common/executeCommands';
 import { Disposable } from '../common/lifecycle';
 import { EventType, TimelineEvent } from '../common/timelineEvent';
 import { toNotificationUri } from '../common/uri';
@@ -172,6 +173,7 @@ export class NotificationsManager extends Disposable implements vscode.TreeDataP
 		}
 
 		const notifications = Array.from(this._notifications.values());
+		this._updateContext();
 		this._onDidChangeNotifications.fire(notifications);
 
 		return {
@@ -180,6 +182,12 @@ export class NotificationsManager extends Disposable implements vscode.TreeDataP
 		};
 	}
 
+	private _updateContext(): void {
+		const notificationCount = this._notifications.size;
+		commands.setContext(contexts.NOTIFICATION_COUNT, notificationCount === 0 ? -1 : notificationCount);
+	}
+
+
 	public getNotification(key: string): NotificationTreeItem | undefined {
 		return this._notifications.get(key);
 	}
@@ -218,6 +226,7 @@ export class NotificationsManager extends Disposable implements vscode.TreeDataP
 
 			this._onDidChangeNotifications.fire([notification]);
 			this._notifications.delete(notificationIdentifier.notificationKey);
+			this._updateContext();
 
 			this._refresh(false);
 		}
@@ -230,6 +239,7 @@ export class NotificationsManager extends Disposable implements vscode.TreeDataP
 
 			this._onDidChangeNotifications.fire([notification]);
 			this._notifications.delete(notificationIdentifier.notificationKey);
+			this._updateContext();
 
 			this._refresh(false);
 		}

src/notifications/notificationsProvider.ts

@@ -5,7 +5,6 @@
 
 import * as vscode from 'vscode';
 import { AuthProvider } from '../common/authentication';
-import { commands, contexts } from '../common/executeCommands';
 import { Disposable } from '../common/lifecycle';
 import { EXPERIMENTAL_NOTIFICATIONS_PAGE_SIZE, PR_SETTINGS_NAMESPACE } from '../common/settingKeys';
 import { OctokitCommon } from '../github/common';
@@ -102,7 +101,6 @@ export class NotificationsProvider extends Disposable {
 			.map((notification: OctokitCommon.Notification) => parseNotification(notification))
 			.filter(notification => !!notification) as Notification[];
 
-		commands.setContext(contexts.NOTIFICATION_COUNT, notifications.length);
 		return { notifications, hasNextPage: headers.link?.includes(`rel="next"`) === true };
 	}