adding monkeytype

frontend/__tests__/components/layout/footer/ScrollToTop.spec.tsx

@@ -0,0 +1,105 @@
+import { render } from "@solidjs/testing-library";
+import { userEvent } from "@testing-library/user-event";
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+import { ScrollToTop } from "../../../../src/ts/components/layout/footer/ScrollToTop";
+import * as CoreSignals from "../../../../src/ts/states/core";
+
+describe("ScrollToTop", () => {
+  const getActivePageMock = vi.spyOn(CoreSignals, "getActivePage");
+  beforeEach(() => {
+    getActivePageMock.mockClear().mockReturnValue("account");
+    Object.defineProperty(window, "scrollY", { value: 0, writable: true });
+  });
+
+  function renderElement(): {
+    container: HTMLElement;
+    button: HTMLButtonElement;
+  } {
+    const { container } = render(() => <ScrollToTop />);
+
+    return {
+      // oxlint-disable-next-line no-non-null-assertion
+      container: container.children[0]! as HTMLElement,
+      // oxlint-disable-next-line no-non-null-assertion
+      button: container.querySelector("button")!,
+    };
+  }
+
+  it("renders with correct classes and structure", () => {
+    const { container, button } = renderElement();
+
+    expect(container).toHaveClass("content-grid", "ScrollToTop");
+    expect(button).toHaveClass("breakout");
+    expect(button.querySelector("i")).toHaveClass("fas", "fa-angle-double-up");
+  });
+
+  it("renders invisible when scrollY is 0", () => {
+    const { button } = renderElement();
+
+    expect(button).toHaveClass("opacity-0");
+  });
+
+  it("becomes visible when scrollY > 100 on non-test pages", () => {
+    const { button } = renderElement();
+    scrollTo(150);
+
+    expect(button).not.toHaveClass("opacity-0");
+  });
+
+  it("stays invisible on test page at scroll 0", () => {
+    getActivePageMock.mockReturnValue("test");
+    const { button } = renderElement();
+
+    expect(button).toHaveClass("opacity-0");
+  });
+
+  it("stays invisible on test page even with scroll > 100", () => {
+    getActivePageMock.mockReturnValue("test");
+    const { button } = renderElement();
+    scrollTo(150);
+
+    expect(button).toHaveClass("opacity-0");
+  });
+
+  it("becomes invisible when scroll < 100 on non-test pages", () => {
+    const { button } = renderElement();
+    scrollTo(150);
+    expect(button).not.toHaveClass("opacity-0");
+
+    scrollTo(50);
+    expect(button).toHaveClass("opacity-0");
+  });
+
+  it("scrolls to top and hides button on click", async () => {
+    const scrollToSpy = vi.fn();
+    window.scrollTo = scrollToSpy;
+    const { button } = renderElement();
+    scrollTo(150);
+
+    await userEvent.click(button);
+
+    expect(scrollToSpy).toHaveBeenCalledWith({
+      top: 0,
+      behavior: "smooth",
+    });
+    expect(button).toHaveClass("opacity-0");
+  });
+
+  it("cleans up scroll listener on unmount", () => {
+    const removeEventListenerSpy = vi.spyOn(window, "removeEventListener");
+    const { unmount } = render(() => <ScrollToTop />);
+
+    unmount();
+
+    expect(removeEventListenerSpy).toHaveBeenCalledWith(
+      "scroll",
+      expect.any(Function),
+    );
+  });
+
+  function scrollTo(value: number): void {
+    Object.defineProperty(window, "scrollY", { value, writable: true });
+    window.dispatchEvent(new Event("scroll"));
+  }
+});