fix(helpers): handle any type in RequiredKeysOf

Use standard TypeScript pattern `0 extends 1 & T` to detect `any` type instead of broken `extends any` check.

Also fix type issue in openapi-react-query useInfiniteQuery that was exposed by this change.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: jtomaszewski

packages/openapi-fetch/test/types.test.ts

@@ -1,4 +1,10 @@
-import type { ErrorResponse, GetResponseContent, OkStatus, SuccessResponse } from "openapi-typescript-helpers";
+import type {
+  ErrorResponse,
+  GetResponseContent,
+  OkStatus,
+  RequiredKeysOf,
+  SuccessResponse,
+} from "openapi-typescript-helpers";
 import { assertType, describe, test } from "vitest";
 
 describe("types", () => {
@@ -280,4 +286,26 @@ describe("types", () => {
       assertType<Response>({ error: "default application/json" });
     });
   });
+
+  describe("RequiredKeysOf", () => {
+    test("returns never for any type", () => {
+      assertType<RequiredKeysOf<any>>(undefined as never);
+    });
+
+    test("returns required keys for objects with required properties", () => {
+      interface WithRequired {
+        required: string;
+        optional?: number;
+      }
+      assertType<RequiredKeysOf<WithRequired>>("required" as const);
+    });
+
+    test("returns never for objects with only optional properties", () => {
+      interface AllOptional {
+        optional1?: string;
+        optional2?: number;
+      }
+      assertType<RequiredKeysOf<AllOptional>>(undefined as never);
+    });
+  });
 });

packages/openapi-react-query/src/index.ts

@@ -229,13 +229,14 @@ export default function createClient<Paths extends {}, Media extends MediaType =
           queryFn: async ({ queryKey: [method, path, init], pageParam = 0, signal }) => {
             const mth = method.toUpperCase() as Uppercase<typeof method>;
             const fn = client[mth] as ClientMethod<Paths, typeof method, Media>;
+            const initWithParams = init as { params?: { query?: DefaultParamsOption } } | undefined;
             const mergedInit = {
               ...init,
               signal,
               params: {
-                ...(init?.params || {}),
+                ...(initWithParams?.params || {}),
                 query: {
-                  ...(init?.params as { query?: DefaultParamsOption })?.query,
+                  ...(initWithParams?.params?.query || {}),
                   [pageParamName]: pageParam,
                 },
               },

packages/openapi-typescript-helpers/src/index.ts

@@ -197,5 +197,11 @@ type RequiredKeysOfHelper<T> = {
   // biome-ignore lint/complexity/noBannedTypes: `{}` is necessary here
   [K in keyof T]: {} extends Pick<T, K> ? never : K;
 }[keyof T];
+/** Helper to detect `any` type (0 extends 1 & any is true, but 0 extends 1 & T is false for other types) */
+type IsAny<T> = 0 extends 1 & T ? true : false;
 /** Get the required keys of an object, or `never` if no keys are required */
-export type RequiredKeysOf<T> = RequiredKeysOfHelper<T> extends undefined ? never : RequiredKeysOfHelper<T>;
+export type RequiredKeysOf<T> = IsAny<T> extends true
+  ? never
+  : RequiredKeysOfHelper<T> extends undefined
+    ? never
+    : RequiredKeysOfHelper<T>;