From e44114092616d2c628eb2a9112f4cdb7854c7a0d Mon Sep 17 00:00:00 2001
From: Tim Laubert <t.laubert@live.de>
Date: Thu, 27 Aug 2026 11:17:45 +0200
Subject: [PATCH 1/2] fix(db): lazily initialize runtime reference identities

---
 .../lazy-runtime-reference-identities.md      |  5 +++++
 .../src/query/runtime-reference-identity.ts   | 14 +++++++++++--
 .../db/tests/query/ir-stable-identity.test.ts | 20 +++++++++++++++++++
 3 files changed, 37 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/lazy-runtime-reference-identities.md

diff --git a/.changeset/lazy-runtime-reference-identities.md b/.changeset/lazy-runtime-reference-identities.md
new file mode 100644
index 0000000000..807b0f5ce7
--- /dev/null
+++ b/.changeset/lazy-runtime-reference-identities.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/db': patch
+---
+
+Lazily initialize runtime reference identities to avoid generating random values during Cloudflare Worker module evaluation.
diff --git a/packages/db/src/query/runtime-reference-identity.ts b/packages/db/src/query/runtime-reference-identity.ts
index 15d7b82b6d..73ed621db0 100644
--- a/packages/db/src/query/runtime-reference-identity.ts
+++ b/packages/db/src/query/runtime-reference-identity.ts
@@ -21,8 +21,18 @@ export function createRuntimeReferenceIdentityFactory(): (
   }
 }
 
-export const getRuntimeReferenceIdentity =
-  createRuntimeReferenceIdentityFactory()
+let runtimeReferenceIdentityFactory:
+  | ReturnType<typeof createRuntimeReferenceIdentityFactory>
+  | undefined
+
+export function getRuntimeReferenceIdentity(
+  value: object,
+): RuntimeReferenceIdentity {
+  runtimeReferenceIdentityFactory ??=
+    createRuntimeReferenceIdentityFactory()
+
+  return runtimeReferenceIdentityFactory(value)
+}
 
 function createRuntimeReferenceNamespace(): string {
   const randomValues = new Uint32Array(4)
diff --git a/packages/db/tests/query/ir-stable-identity.test.ts b/packages/db/tests/query/ir-stable-identity.test.ts
index ca745d9de5..a412f2e0b4 100644
--- a/packages/db/tests/query/ir-stable-identity.test.ts
+++ b/packages/db/tests/query/ir-stable-identity.test.ts
@@ -309,6 +309,26 @@ describe(`semantic expression identity`, () => {
     },
   )
 
+  it(`does not initialize runtime reference identities during module evaluation`, async () => {
+    const getRandomValues = vi.fn((values: Uint32Array) => values)
+    vi.stubGlobal(`crypto`, { getRandomValues })
+    vi.resetModules()
+
+    try {
+      const { getRuntimeReferenceIdentity } =
+        await import(`../../src/query/runtime-reference-identity.js`)
+
+      expect(getRandomValues).not.toHaveBeenCalled()
+
+      getRuntimeReferenceIdentity({})
+      getRuntimeReferenceIdentity({})
+
+      expect(getRandomValues).toHaveBeenCalledOnce()
+    } finally {
+      vi.unstubAllGlobals()
+    }
+  })
+
   it(`does not reuse reference identities across runtimes`, () => {
     const firstRuntime = createRuntimeReferenceIdentityFactory()
     const secondRuntime = createRuntimeReferenceIdentityFactory()

From cc607e74bf1f0ea5a53540ac774966f54689442e Mon Sep 17 00:00:00 2001
From: "autofix-ci[bot]" <114827586+autofix-ci[bot]@users.noreply.github.com>
Date: Thu, 27 Aug 2026 16:26:35 +0000
Subject: [PATCH 2/2] ci: apply automated fixes

---
 packages/db/src/query/runtime-reference-identity.ts | 3 +--
 packages/db/tests/query/ir-stable-identity.test.ts  | 5 +++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/db/src/query/runtime-reference-identity.ts b/packages/db/src/query/runtime-reference-identity.ts
index 73ed621db0..e41aeaf67a 100644
--- a/packages/db/src/query/runtime-reference-identity.ts
+++ b/packages/db/src/query/runtime-reference-identity.ts
@@ -28,8 +28,7 @@ let runtimeReferenceIdentityFactory:
 export function getRuntimeReferenceIdentity(
   value: object,
 ): RuntimeReferenceIdentity {
-  runtimeReferenceIdentityFactory ??=
-    createRuntimeReferenceIdentityFactory()
+  runtimeReferenceIdentityFactory ??= createRuntimeReferenceIdentityFactory()
 
   return runtimeReferenceIdentityFactory(value)
 }
diff --git a/packages/db/tests/query/ir-stable-identity.test.ts b/packages/db/tests/query/ir-stable-identity.test.ts
index a412f2e0b4..6b730cbda3 100644
--- a/packages/db/tests/query/ir-stable-identity.test.ts
+++ b/packages/db/tests/query/ir-stable-identity.test.ts
@@ -315,8 +315,9 @@ describe(`semantic expression identity`, () => {
     vi.resetModules()
 
     try {
-      const { getRuntimeReferenceIdentity } =
-        await import(`../../src/query/runtime-reference-identity.js`)
+      const { getRuntimeReferenceIdentity } = await import(
+        `../../src/query/runtime-reference-identity.js`
+      )
 
       expect(getRandomValues).not.toHaveBeenCalled()