From 1dc5b28b94b4a63f735a42d6497d538434d69b66 Mon Sep 17 00:00:00 2001
From: Ron Buckton <ron.buckton@microsoft.com>
Date: Mon, 30 Jan 2023 22:23:29 -0500
Subject: [PATCH] Restore global `onProfilerEvent` hook for ts-perf (#52523)

---
 src/compiler/performance.ts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/compiler/performance.ts b/src/compiler/performance.ts
index 166163784ab..4f2096ec720 100644
--- a/src/compiler/performance.ts
+++ b/src/compiler/performance.ts
@@ -11,6 +11,9 @@ import {
 
 /** Performance measurements for the compiler. */
 
+// NOTE: declared global is injected by ts-perf to monitor profiler marks to generate heap snapshots.
+declare let onProfilerEvent: ((eventName: string) => void) | undefined;
+
 let perfHooks: PerformanceHooks | undefined;
 // when set, indicates the implementation of `Performance` to use for user timing.
 // when unset, indicates user timing is unavailable or disabled.
@@ -74,6 +77,9 @@ export function mark(markName: string) {
         counts.set(markName, count + 1);
         marks.set(markName, timestamp());
         performanceImpl?.mark(markName);
+        if (typeof onProfilerEvent === "function") {
+            onProfilerEvent(markName);
+        }
     }
 }