test(useInfiniteScroll): 스크롤을 끝까지 내렸을 때 fetchNextPage 호출 확인

src/hooks/useInfiniteScroll.spec.tsx

@@ -0,0 +1,25 @@
+import { fireEvent, renderHook } from "@testing-library/react";
+import useInfiniteScroll from "./useInfiniteScroll";
+
+describe("useInfiniteScroll", () => {
+  it("스크롤을 끝까지 내렸을 때 fetchNextPage 호출 확인", () => {
+    const fetchNextPage = jest.fn();
+    renderHook(() => useInfiniteScroll(fetchNextPage));
+
+    Object.defineProperty(window, "scrollY", {
+      writable: true,
+      configurable: true,
+      value: 0,
+    });
+    Object.defineProperty(document.documentElement, "offsetHeight", {
+      writable: true,
+      configurable: true,
+      value: 3000,
+    });
+
+    window.scrollY = 3000;
+
+    fireEvent.scroll(window);
+    expect(fetchNextPage).toHaveBeenCalled();
+  });
+});