fix(types): do not drop readonly for partial QueryFilter matching (#9872)

* fix(types): do not drop readonly for partial QueryFilter matching

* Create new-keys-raise.md

Author: TkDodo

.changeset/new-keys-raise.md

@@ -0,0 +1,5 @@
+---
+"@tanstack/query-core": patch
+---
+
+fix(types): do not drop readonly for partial QueryFilter matching

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

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 []