From 5350280057c9c7bfdb9a56dfe542f60eac015723 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Sat, 15 Aug 2026 12:57:02 +0200
Subject: [PATCH] Modernize the `XRefMock` unit-test helper

---
 test/unit/name_number_tree_spec.js | 10 ++++----
 test/unit/primitives_spec.js       |  2 +-
 test/unit/test_utils.js            | 38 ++++++++++++++++--------------
 3 files changed, 26 insertions(+), 24 deletions(-)

diff --git a/test/unit/name_number_tree_spec.js b/test/unit/name_number_tree_spec.js
index 3432c51101a8b..48e5103dbb8ce 100644
--- a/test/unit/name_number_tree_spec.js
+++ b/test/unit/name_number_tree_spec.js
@@ -21,7 +21,7 @@ import { XRefMock } from "./test_utils.js";
 describe("NameOrNumberTree", function () {
   describe("NameTree", function () {
     it("should return an empty map when root is null", function () {
-      const xref = new XRefMock([]);
+      const xref = new XRefMock();
       const tree = new NameTree(null, xref);
       expect(tree.getAll().size).toEqual(0);
     });
@@ -30,7 +30,7 @@ describe("NameOrNumberTree", function () {
       const root = new Dict();
       root.set("Names", ["alpha", "value_a", "beta", "value_b"]);
 
-      const xref = new XRefMock([]);
+      const xref = new XRefMock();
       const tree = new NameTree(root, xref);
       const map = tree.getAll();
 
@@ -66,7 +66,7 @@ describe("NameOrNumberTree", function () {
       const root = new Dict();
       root.set("Kids", [inlineLeaf]);
 
-      const xref = new XRefMock([]);
+      const xref = new XRefMock();
       const tree = new NameTree(root, xref);
 
       // Should not throw even though the kid is an inline Dict (not a Ref).
@@ -126,7 +126,7 @@ describe("NameOrNumberTree", function () {
       const root = new Dict();
       root.set("Nums", [1, "one", 2, "two"]);
 
-      const xref = new XRefMock([]);
+      const xref = new XRefMock();
       const tree = new NumberTree(root, xref);
       const map = tree.getAll();
 
@@ -144,7 +144,7 @@ describe("NameOrNumberTree", function () {
       const root = new Dict();
       root.set("Kids", [inlineLeaf]);
 
-      const xref = new XRefMock([]);
+      const xref = new XRefMock();
       const tree = new NumberTree(root, xref);
 
       const map = tree.getAll();
diff --git a/test/unit/primitives_spec.js b/test/unit/primitives_spec.js
index c047dfa615856..fb31e53f08da1 100644
--- a/test/unit/primitives_spec.js
+++ b/test/unit/primitives_spec.js
@@ -127,7 +127,7 @@ describe("primitives", function () {
       const dict = new Dict(null);
       expect(dict.xref).toBeNull();
 
-      const xref = new XRefMock([]);
+      const xref = new XRefMock();
       dict.assignXref(xref);
       expect(dict.xref).toEqual(xref);
     });
diff --git a/test/unit/test_utils.js b/test/unit/test_utils.js
index cd1cbea0aa054..02e1e0bb92f9d 100644
--- a/test/unit/test_utils.js
+++ b/test/unit/test_utils.js
@@ -123,36 +123,38 @@ function getCrossOriginHostname(hostname) {
 }
 
 class XRefMock {
-  constructor(array) {
-    this._map = Object.create(null);
-    this._newTemporaryRefNum = null;
-    this._newPersistentRefNum = null;
-    this.stream = new NullStream();
-
-    for (const key in array) {
-      const obj = array[key];
-      this._map[obj.ref.toString()] = obj.data;
+  #map = new Map();
+
+  #newPersistentRefNum = null;
+
+  #newTemporaryRefNum = null;
+
+  stream = new NullStream();
+
+  constructor(array = []) {
+    for (const { ref, data } of array) {
+      this.#map.set(ref.toString(), data);
     }
   }
 
   getNewPersistentRef(obj) {
-    if (this._newPersistentRefNum === null) {
-      this._newPersistentRefNum = Object.keys(this._map).length || 1;
+    if (this.#newPersistentRefNum === null) {
+      this.#newPersistentRefNum = this.#map.size || 1;
     }
-    const ref = Ref.get(this._newPersistentRefNum++, 0);
-    this._map[ref.toString()] = obj;
+    const ref = Ref.get(this.#newPersistentRefNum++, 0);
+    this.#map.set(ref.toString(), obj);
     return ref;
   }
 
   getNewTemporaryRef() {
-    if (this._newTemporaryRefNum === null) {
-      this._newTemporaryRefNum = Object.keys(this._map).length || 1;
+    if (this.#newTemporaryRefNum === null) {
+      this.#newTemporaryRefNum = this.#map.size || 1;
     }
-    return Ref.get(this._newTemporaryRefNum++, 0);
+    return Ref.get(this.#newTemporaryRefNum++, 0);
   }
 
   resetNewTemporaryRef() {
-    this._newTemporaryRefNum = null;
+    this.#newTemporaryRefNum = null;
   }
 
   countUpdatesAfter(offset) {
@@ -160,7 +162,7 @@ class XRefMock {
   }
 
   fetch(ref) {
-    return this._map[ref.toString()];
+    return this.#map.get(ref.toString());
   }
 
   async fetchAsync(ref) {