From b22e80215d04ec57c38cffcca7ef802a77d059ae Mon Sep 17 00:00:00 2001
From: zodern <zodern@users.noreply.github.com>
Date: Fri, 15 Oct 2021 12:14:56 -0500
Subject: [PATCH] Avoid creating nested recursive watchers

---
 tools/fs/safe-watcher.ts | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/tools/fs/safe-watcher.ts b/tools/fs/safe-watcher.ts
index 467127acaa..4c8bd9f6d6 100644
--- a/tools/fs/safe-watcher.ts
+++ b/tools/fs/safe-watcher.ts
@@ -6,7 +6,8 @@ import {
   convertToOSPath,
   watchFile,
   unwatchFile,
-  toPosixPath
+  toPosixPath,
+  pathRelative
 } from "./files";
 
 import {
@@ -439,6 +440,23 @@ export function addWatchRoot(absPath: string) {
   }
 
   watchRoots.add(absPath);
+  
+  // If there already is a watcher for a parent directory, there is no need
+  // to create this watcher.
+  for (const path of watchRoots) {
+    let relativePath = pathRelative(path, absPath);
+    if (
+      path !== absPath &&
+      !relativePath.startsWith('..') &&
+      !relativePath.startsWith('/')
+    ) {
+      return;
+    }
+  }
+
+  // TODO: check if there are any existing watchers that are children of this
+  // watcher and stop them
+
   nsfw(
     convertToOSPath(absPath),
     (events) => {