From 027689121f6f97a6539cbc41c9629592e48dd6a2 Mon Sep 17 00:00:00 2001
From: thribhuvan003 <thribhuvan003@gmail.com>
Date: Tue, 25 Aug 2026 21:18:29 +0530
Subject: [PATCH] fix(solid-query): allow optional initialData in
 infiniteQueryOptions

UndefinedInitialDataInfiniteOptions typed initialData as `?: undefined`, so
passing a value that may be undefined matched neither overload: the defined
one rejects undefined, and the undefined one rejects the data. Callers had to
cast or split the call.

Widen the union to accept the data and its function form, matching the shape
react-query has had since #8157 and mirroring solid's own
DefinedInitialDataInfiniteOptions.
---
 .changeset/olive-pugs-repeat.md               |  5 +++++
 .../__tests__/infiniteQueryOptions.test-d.tsx | 19 +++++++++++++++++++
 .../solid-query/src/infiniteQueryOptions.ts   |  5 ++++-
 3 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/olive-pugs-repeat.md

diff --git a/.changeset/olive-pugs-repeat.md b/.changeset/olive-pugs-repeat.md
new file mode 100644
index 00000000000..99e5ae99947
--- /dev/null
+++ b/.changeset/olive-pugs-repeat.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/solid-query': patch
+---
+
+Allow optional `initialData` in `infiniteQueryOptions`, matching react-query
diff --git a/packages/solid-query/src/__tests__/infiniteQueryOptions.test-d.tsx b/packages/solid-query/src/__tests__/infiniteQueryOptions.test-d.tsx
index be3a19cb97d..fb017d7411d 100644
--- a/packages/solid-query/src/__tests__/infiniteQueryOptions.test-d.tsx
+++ b/packages/solid-query/src/__tests__/infiniteQueryOptions.test-d.tsx
@@ -136,4 +136,23 @@ describe('infiniteQueryOptions', () => {
       }>
     >()
   })
+
+  it('should allow optional initialData object', () => {
+    const initialData = { wow: true } as { wow: boolean } | undefined
+    const options = infiniteQueryOptions({
+      queryKey: queryKey(),
+      queryFn: () => initialData,
+      initialData: initialData
+        ? { pages: [initialData], pageParams: [] }
+        : undefined,
+      getNextPageParam: () => 1,
+      initialPageParam: 1,
+    })
+
+    expectTypeOf(options.initialData).toExtend<
+      | InfiniteData<{ wow: boolean } | undefined, number>
+      | (() => InfiniteData<{ wow: boolean } | undefined, number>)
+      | undefined
+    >()
+  })
 })
diff --git a/packages/solid-query/src/infiniteQueryOptions.ts b/packages/solid-query/src/infiniteQueryOptions.ts
index 1648882d2f3..984347653bf 100644
--- a/packages/solid-query/src/infiniteQueryOptions.ts
+++ b/packages/solid-query/src/infiniteQueryOptions.ts
@@ -16,7 +16,10 @@ export type UndefinedInitialDataInfiniteOptions<
   TPageParam = unknown,
 > = Accessor<
   InfiniteQueryOptions<TQueryFnData, TError, TData, TQueryKey, TPageParam> & {
-    initialData?: undefined
+    initialData?:
+      | undefined
+      | NonUndefinedGuard<InfiniteData<TQueryFnData, TPageParam>>
+      | (() => NonUndefinedGuard<InfiniteData<TQueryFnData, TPageParam>>)
   }
 >