From 1e23b1420bb6ded4791d6f2d9b7116a6ad30eebb Mon Sep 17 00:00:00 2001
From: Adrian Niculescu <15037449+adrian-niculescu@users.noreply.github.com>
Date: Tue, 6 Oct 2026 20:57:45 +0300
Subject: [PATCH] fix(worker): throw when an environment-data key cannot be
 converted to a string

setEnvironmentData and getEnvironmentData converted the key with a helper that swallows a throwing toString() and returns an empty string, so such a key silently read, overwrote or deleted the unrelated empty-string entry. The conversion is checked now and the exception reaches the caller.
---
 .../main/assets/app/tests/testMessaging.js    | 46 +++++++++++++++++++
 test-app/runtime/src/main/cpp/Messaging.cpp   | 21 ++++++++-
 2 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/test-app/app/src/main/assets/app/tests/testMessaging.js b/test-app/app/src/main/assets/app/tests/testMessaging.js
index c06a46037..375f8aadf 100644
--- a/test-app/app/src/main/assets/app/tests/testMessaging.js
+++ b/test-app/app/src/main/assets/app/tests/testMessaging.js
@@ -204,6 +204,52 @@ describe("Messaging runtime edges", function () {
         });
     });
 
+    describe("environment data keys", function () {
+        it("keeps keys containing NUL distinct from their prefixes", function () {
+            var wt = require("node:worker_threads");
+            var prefix = "environment-key";
+            var key = prefix + "\0suffix";
+            try {
+                wt.setEnvironmentData(prefix, "prefix");
+                wt.setEnvironmentData(key, "full key");
+                expect(wt.getEnvironmentData(prefix)).toBe("prefix");
+                expect(wt.getEnvironmentData(key)).toBe("full key");
+                wt.setEnvironmentData(key);
+                expect(wt.getEnvironmentData(key)).toBeUndefined();
+                expect(wt.getEnvironmentData(prefix)).toBe("prefix");
+            } finally {
+                wt.setEnvironmentData(key);
+                wt.setEnvironmentData(prefix);
+            }
+        });
+
+        function thrownMessage(fn) {
+            try {
+                fn();
+            } catch (e) {
+                return e && e.message;
+            }
+            return "nothing thrown";
+        }
+
+        it("throws what a key's toString throws instead of using the empty-string key", function () {
+            var wt = require("node:worker_threads");
+            var key = { toString: function () { throw new Error("key toString failed"); } };
+            wt.setEnvironmentData("", "empty");
+            try {
+                expect(thrownMessage(function () { wt.setEnvironmentData(key, "other"); }))
+                    .toBe("key toString failed");
+                expect(thrownMessage(function () { wt.getEnvironmentData(key); }))
+                    .toBe("key toString failed");
+                expect(thrownMessage(function () { wt.setEnvironmentData(key); }))
+                    .toBe("key toString failed");
+                expect(wt.getEnvironmentData("")).toBe("empty");
+            } finally {
+                wt.setEnvironmentData("");
+            }
+        });
+    });
+
     describe("worker error reporting", function () {
         // A worker boots on its own thread, so the first error arrives whenever
         // the runner gets to it; specs wait for it and only then settle for
diff --git a/test-app/runtime/src/main/cpp/Messaging.cpp b/test-app/runtime/src/main/cpp/Messaging.cpp
index 0d0f873f1..311f7d757 100644
--- a/test-app/runtime/src/main/cpp/Messaging.cpp
+++ b/test-app/runtime/src/main/cpp/Messaging.cpp
@@ -935,13 +935,27 @@ void SetEmitMessageCallback(const FunctionCallbackInfo<Value>& info) {
     state->emitMessage.Reset(isolate, info[0].As<v8::Function>());
 }
 
+// The key as the string the store files it under. A key whose conversion throws
+// leaves that exception pending for the caller rather than standing in for "".
+static bool EnvironmentDataKey(Isolate* isolate, Local<Value> value, std::string& key) {
+    Local<v8::String> str;
+    if (!value->ToString(isolate->GetCurrentContext()).ToLocal(&str)) {
+        return false;
+    }
+    key = ArgConverter::ToString(isolate, str);
+    return true;
+}
+
 void SetEnvironmentDataCallback(const FunctionCallbackInfo<Value>& info) {
     Isolate* isolate = info.GetIsolate();
     if (info.Length() < 1) {
         return;
     }
     Local<Context> context = isolate->GetCurrentContext();
-    std::string key = ArgConverter::ToString(isolate, info[0]);
+    std::string key;
+    if (!EnvironmentDataKey(isolate, info[0], key)) {
+        return;
+    }
     if (info.Length() < 2 || info[1]->IsUndefined()) {
         std::lock_guard<std::mutex> lock(g_environmentDataMutex);
         g_environmentData.erase(key);
@@ -964,7 +978,10 @@ void GetEnvironmentDataCallback(const FunctionCallbackInfo<Value>& info) {
     if (info.Length() < 1) {
         return;
     }
-    std::string key = ArgConverter::ToString(isolate, info[0]);
+    std::string key;
+    if (!EnvironmentDataKey(isolate, info[0], key)) {
+        return;
+    }
     std::shared_ptr<serialization::SerializedValue> stored;
     {
         std::lock_guard<std::mutex> lock(g_environmentDataMutex);