From a1803347d9eb65a349eb53c9fb0d75c39944fa00 Mon Sep 17 00:00:00 2001
From: Ashcon Partovi <ashcon@partovi.net>
Date: Tue, 30 Apr 2024 11:02:01 -0700
Subject: [PATCH 1/2] Better stubs for
 `perf_hooks.{createHistogram,monitorEventLoopDelay}`

---
 src/js/node/perf_hooks.ts                  | 104 +++++++++++++++++++--
 test/js/node/perf_hooks/perf_hooks.test.ts |   7 +-
 2 files changed, 101 insertions(+), 10 deletions(-)

diff --git a/src/js/node/perf_hooks.ts b/src/js/node/perf_hooks.ts
index b23e40b860d70..6798a39243ab1 100644
--- a/src/js/node/perf_hooks.ts
+++ b/src/js/node/perf_hooks.ts
@@ -1,5 +1,5 @@
 // Hardcoded module "node:perf_hooks"
-const { throwNotImplemented } = require("internal/shared");
+const { warnNotImplementedOnce } = require("internal/shared");
 
 var {
   Performance,
@@ -80,6 +80,7 @@ function createPerformanceNodeTiming() {
 }
 
 function eventLoopUtilization(utilization1, utilization2) {
+  warnNotImplementedOnce("perf_hooks.eventLoopUtilization");
   return {
     idle: 0,
     active: 0,
@@ -87,6 +88,99 @@ function eventLoopUtilization(utilization1, utilization2) {
   };
 }
 
+// https://nodejs.org/api/perf_hooks.html#class-histogram
+// https://github.com/nodejs/node/blob/5976985a58a8635b8f1272519020c817f4ccdd1b/src/histogram.h#L25
+class Histogram {
+  count: number;
+  countBigInt: bigint;
+  exceeds: number;
+  exceedsBigInt: bigint;
+  max: number;
+  maxBigInt: bigint;
+  mean: number;
+  min: number;
+  minBigInt: bigint;
+  percentiles: Map<number, number>;
+  percentilesBigInt: Map<number, bigint>;
+  stddev: number;
+
+  constructor() {
+    this.count = 0;
+    this.countBigInt = 0n;
+    this.exceeds = 0;
+    this.exceedsBigInt = 0n;
+    this.max = 0;
+    this.maxBigInt = 0n;
+    this.mean = 0;
+    this.min = 0;
+    this.minBigInt = 0n;
+    this.percentiles = new Map();
+    this.percentilesBigInt = new Map();
+    this.stddev = 0;
+  }
+
+  percentile(p: number) {
+    return 0;
+  }
+
+  percentileBigInt(p: number) {
+    return 0n;
+  }
+
+  reset() {
+    this.percentiles.clear();
+    this.percentilesBigInt.clear();
+  }
+}
+
+class IntervalHistogram extends Histogram {
+  #enabled: boolean = false;
+
+  enable() {
+    const wasEnabled = this.#enabled;
+    if (!wasEnabled) {
+      this.#enabled = true;
+    }
+    return wasEnabled;
+  }
+
+  disable() {
+    const wasEnabled = this.#enabled;
+    if (wasEnabled) {
+      this.#enabled = false;
+    }
+    return wasEnabled;
+  }
+}
+
+class RecordableHistogram extends Histogram {
+  constructor(options?: unknown) {
+    super();
+  }
+
+  add(other: RecordableHistogram) {
+    // TODO
+  }
+
+  record(value: number | bigint) {
+    // TODO
+  }
+
+  recordDelta() {
+    // TODO
+  }
+}
+
+function createHistogram(options) {
+  warnNotImplementedOnce("perf_hooks.createHistogram");
+  return new RecordableHistogram(options);
+}
+
+function monitorEventLoopDelay() {
+  warnNotImplementedOnce("perf_hooks.monitorEventLoopDelay");
+  return new IntervalHistogram();
+}
+
 // PerformanceEntry is not a valid constructor, so we have to fake it.
 class PerformanceResourceTiming {
   constructor() {
@@ -155,11 +249,7 @@ export default {
   PerformanceObserver,
   PerformanceObserverEntryList,
   PerformanceNodeTiming,
-  monitorEventLoopDelay() {
-    throwNotImplemented("perf_hooks.monitorEventLoopDelay");
-  },
-  createHistogram() {
-    throwNotImplemented("perf_hooks.createHistogram");
-  },
   PerformanceResourceTiming,
+  monitorEventLoopDelay,
+  createHistogram,
 };
diff --git a/test/js/node/perf_hooks/perf_hooks.test.ts b/test/js/node/perf_hooks/perf_hooks.test.ts
index 61a75d49b9d8b..fa93f2f693dd0 100644
--- a/test/js/node/perf_hooks/perf_hooks.test.ts
+++ b/test/js/node/perf_hooks/perf_hooks.test.ts
@@ -2,13 +2,14 @@ import perf from "perf_hooks";
 import { test, expect } from "bun:test";
 
 test("stubs", () => {
-  expect(() => perf.monitorEventLoopDelay()).toThrow();
-  expect(() => perf.createHistogram()).toThrow();
   expect(perf.performance.nodeTiming).toBeObject();
-
   expect(perf.performance.now()).toBeNumber();
   expect(perf.performance.timeOrigin).toBeNumber();
   expect(perf.performance.eventLoopUtilization()).toBeObject();
+  expect(perf.createHistogram).toBeFunction();
+  expect(perf.createHistogram()).toBeObject();
+  expect(perf.monitorEventLoopDelay).toBeFunction();
+  expect(perf.monitorEventLoopDelay()).toBeObject();
 });
 
 test("doesn't throw", () => {

From 7fd67a4151e349f4d6d155dc908c162bb600cf8b Mon Sep 17 00:00:00 2001
From: Ashcon Partovi <ashcon@partovi.net>
Date: Tue, 30 Apr 2024 11:30:04 -0700
Subject: [PATCH 2/2] Fix missing import

---
 src/js/node/perf_hooks.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/js/node/perf_hooks.ts b/src/js/node/perf_hooks.ts
index 6798a39243ab1..dca9f5241e1ab 100644
--- a/src/js/node/perf_hooks.ts
+++ b/src/js/node/perf_hooks.ts
@@ -1,5 +1,5 @@
 // Hardcoded module "node:perf_hooks"
-const { warnNotImplementedOnce } = require("internal/shared");
+const { throwNotImplemented, warnNotImplementedOnce } = require("internal/shared");
 
 var {
   Performance,