From 3016866a4bc67b570e32ddd0fb4bbacac839f435 Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Tue, 26 Sep 2023 18:30:39 +0100
Subject: [PATCH] Make the right function a real function, then the 'this'
 param works

---
 src/settings/rageshake.ts | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/src/settings/rageshake.ts b/src/settings/rageshake.ts
index d3aaf1dc..6ded0c2d 100644
--- a/src/settings/rageshake.ts
+++ b/src/settings/rageshake.ts
@@ -551,10 +551,10 @@ type StringifyReplacer = (
 
 // From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Cyclic_object_value#circular_references
 // Injects `<$ cycle-trimmed $>` wherever it cuts a cyclical object relationship
-const getCircularReplacer = function (): StringifyReplacer {
+const getCircularReplacer = (): StringifyReplacer => {
   const seen = new WeakSet();
   const depthMap = new WeakMap<object, number>();
-  return (key: string, value: unknown): unknown => {
+  return function (this: unknown, key: string, value: unknown): unknown {
     if (typeof value === "object" && value !== null) {
       if (seen.has(value)) {
         return "<$ cycle-trimmed $>";
@@ -562,17 +562,10 @@ const getCircularReplacer = function (): StringifyReplacer {
       seen.add(value);
 
       let depth = 0;
-      if (key) {
-        depth = depthMap.get(value) ?? 0;
-      }
-
-      // 'this' is supposed to be the object the value was found in, according to
-      // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
-      // but that doesn't seem to be the case. Instead, we do a pre-pass on the children here to
-      // remember what depth we saw them at.
-      for (const v of Object.values(value)) {
-        if (typeof v === "object") depthMap.set(v, depth + 1);
+      if (this) {
+        depth = depthMap.get(this) ?? 0;
       }
+      depthMap.set(value, depth + 1);
 
       if (depth > DEPTH_LIMIT) return "<$ object-pruned $>";
     }