From 6c0c7978db89855cf1203e0102c354a9ae741078 Mon Sep 17 00:00:00 2001
From: TkDodo <office@dorfmeister.cc>
Date: Fri, 14 Nov 2025 09:06:43 +0100
Subject: [PATCH 1/2] fix(types): do not drop readonly for partial QueryFilter
 matching

---
 packages/query-core/src/__tests__/utils.test-d.tsx | 14 +++++++++++++-
 packages/query-core/src/utils.ts                   |  2 +-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/packages/query-core/src/__tests__/utils.test-d.tsx b/packages/query-core/src/__tests__/utils.test-d.tsx
index 3aacc61b81..8c87636e9a 100644
--- a/packages/query-core/src/__tests__/utils.test-d.tsx
+++ b/packages/query-core/src/__tests__/utils.test-d.tsx
@@ -50,7 +50,7 @@ describe('QueryFilters', () => {
     expectTypeOf(filters.queryKey).toEqualTypeOf<
       | undefined
       | readonly []
-      | ['key']
+      | readonly ['key']
       | readonly [
           'key',
           {
@@ -61,6 +61,18 @@ describe('QueryFilters', () => {
     >()
   })
 
+  it('should work with readonly union types', () => {
+    const filters: QueryFilters<
+      readonly ['key'] | readonly ['key', 'something']
+    > = {
+      queryKey: ['key'],
+    }
+
+    expectTypeOf(filters.queryKey).toEqualTypeOf<
+      undefined | readonly [] | readonly ['key'] | readonly ['key', 'something']
+    >()
+  })
+
   it('should error on invalid query keys', () => {
     assertType<QueryFilters<readonly ['key', { a: number; b: string }]>>({
       // @ts-expect-error cannot pass invalid query key
diff --git a/packages/query-core/src/utils.ts b/packages/query-core/src/utils.ts
index 1be53edd2d..7f3baf25fc 100644
--- a/packages/query-core/src/utils.ts
+++ b/packages/query-core/src/utils.ts
@@ -20,7 +20,7 @@ type DropLast<T extends ReadonlyArray<unknown>> = T extends readonly [
   ...infer R,
   unknown,
 ]
-  ? R
+  ? readonly [...R]
   : never
 
 type TuplePrefixes<T extends ReadonlyArray<unknown>> = T extends readonly []

From f918a31c1fe2c8b8b7603638a6daa5f8f7645c98 Mon Sep 17 00:00:00 2001
From: Dominik Dorfmeister <office@dorfmeister.cc>
Date: Fri, 14 Nov 2025 09:14:18 +0100
Subject: [PATCH 2/2] Create new-keys-raise.md

---
 .changeset/new-keys-raise.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/new-keys-raise.md

diff --git a/.changeset/new-keys-raise.md b/.changeset/new-keys-raise.md
new file mode 100644
index 0000000000..ac6729f13c
--- /dev/null
+++ b/.changeset/new-keys-raise.md
@@ -0,0 +1,5 @@
+---
+"@tanstack/query-core": patch
+---
+
+fix(types): do not drop readonly for partial QueryFilter matching