import { render } from "@testing-library/react";
import ScrollProgress from "./ScrollProgress";

describe("ScrollProgress", () => {
  it("is decorative: hidden from assistive technology, with no text", () => {
    const { container } = render(<ScrollProgress />);

    for (const piece of container.querySelectorAll(".ds-scroll-progress"))
      expect(piece).toHaveAttribute("aria-hidden", "true");
    expect(container).toHaveTextContent("");
  });

  it("has the top bar and the side rail with its fill and dot, ready for the CSS scroll timeline", () => {
    const { container } = render(<ScrollProgress />);

    expect(container.querySelector(".ds-scroll-bar")).toBeInTheDocument();
    expect(
      container.querySelector(".ds-scroll-rail .ds-scroll-fill"),
    ).toBeInTheDocument();
    expect(
      container.querySelector(".ds-scroll-rail .ds-scroll-dot"),
    ).toBeInTheDocument();
  });

  it("drives nothing from JavaScript: no inline transform or opacity, no scroll listener", () => {
    const listen = jest.spyOn(window, "addEventListener");
    const { container } = render(<ScrollProgress />);

    for (const element of container.querySelectorAll<HTMLElement>("*")) {
      expect(element.style.transform).toBe("");
      expect(element.style.opacity).toBe("");
    }
    expect(listen.mock.calls.map(([type]) => type)).not.toContain("scroll");
    listen.mockRestore();
  });

  it("does not need the animation library", () => {
    jest.isolateModules(() => {
      // o pacote "motion" saiu do projeto: virtual, para o dublê valer mesmo sem ele no node_modules
      jest.doMock(
        "motion/react",
        () => {
          throw new Error(
            "motion não pode ser carregado pela barra de rolagem",
          );
        },
        { virtual: true },
      );
      expect(() => require("./ScrollProgress")).not.toThrow();
    });
  });
});