From f8067ffadab178d2929a162408032ff63b0b717b Mon Sep 17 00:00:00 2001
From: Chris LaFreniere <40371649+chlafreniere@users.noreply.github.com>
Date: Thu, 24 Oct 2019 22:14:24 -0700
Subject: [PATCH] Fix for Markdown File in Jupyter Books Viewlet not Opening
 After 2x (#8009)

* fix for markdown not opening after opened twice

* PR comment to add return type
---
 extensions/notebook/src/book/bookTreeView.ts | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/extensions/notebook/src/book/bookTreeView.ts b/extensions/notebook/src/book/bookTreeView.ts
index 17df14203d..afe4e48a40 100644
--- a/extensions/notebook/src/book/bookTreeView.ts
+++ b/extensions/notebook/src/book/bookTreeView.ts
@@ -203,8 +203,7 @@ export class BookTreeViewProvider implements vscode.TreeDataProvider<BookTreeIte
 	private runThrottledAction(resource: string, action: () => void) {
 		const isResourceChange = resource !== this._resource;
 		if (isResourceChange) {
-			clearTimeout(this._throttleTimer);
-			this._throttleTimer = undefined;
+			this.clearAndResetThrottleTimer();
 		}
 
 		this._resource = resource;
@@ -214,11 +213,19 @@ export class BookTreeViewProvider implements vscode.TreeDataProvider<BookTreeIte
 			if (isResourceChange) {
 				action();
 			} else {
-				this._throttleTimer = setTimeout(() => action(), 300);
+				this._throttleTimer = setTimeout(() => {
+					action();
+					this.clearAndResetThrottleTimer();
+				}, 300);
 			}
 		}
 	}
 
+	private clearAndResetThrottleTimer(): void {
+		clearTimeout(this._throttleTimer);
+		this._throttleTimer = undefined;
+	}
+
 	openExternalLink(resource: string): void {
 		try {
 			vscode.env.openExternal(vscode.Uri.parse(resource));