one/dist/cjs/link/prefetchViewport.test.cjs

One is a new React Framework that makes Vite serve both native and web.

var import_vitest = require("vitest");
var import_prefetchViewport = require("./prefetchViewport.cjs");
let mockIOCallback;
const mockObserved = /* @__PURE__ */new Set();
import_vitest.vi.stubGlobal("IntersectionObserver", class {
  constructor(callback) {
    mockIOCallback = callback;
  }
  observe(el) {
    mockObserved.add(el);
  }
  unobserve(el) {
    mockObserved.delete(el);
  }
  disconnect() {
    mockObserved.clear();
  }
});
function simulateIntersect(el, isIntersecting) {
  mockIOCallback([{
    target: el,
    isIntersecting
  }], {});
}
(0, import_vitest.describe)("prefetchViewport", () => {
  let prefetched;
  let vp;
  (0, import_vitest.beforeEach)(() => {
    prefetched = [];
    mockObserved.clear();
    vp = (0, import_prefetchViewport.createPrefetchViewport)();
    vp.start(href => prefetched.push(href));
  });
  (0, import_vitest.it)("prefetches when link enters viewport", () => {
    const el = {};
    vp.observe(el, "/about");
    simulateIntersect(el, true);
    (0, import_vitest.expect)(prefetched).toEqual(["/about"]);
  });
  (0, import_vitest.it)("does not prefetch when link exits viewport", () => {
    const el = {};
    vp.observe(el, "/about");
    simulateIntersect(el, false);
    (0, import_vitest.expect)(prefetched).toEqual([]);
  });
  (0, import_vitest.it)("only prefetches each href once", () => {
    const el = {};
    vp.observe(el, "/about");
    simulateIntersect(el, true);
    simulateIntersect(el, false);
    simulateIntersect(el, true);
    (0, import_vitest.expect)(prefetched).toEqual(["/about"]);
  });
  (0, import_vitest.it)("cleanup re-enables prefetch for href", () => {
    const el = {};
    const cleanup = vp.observe(el, "/about");
    simulateIntersect(el, true);
    (0, import_vitest.expect)(prefetched).toEqual(["/about"]);
    cleanup();
    prefetched.length = 0;
    vp.observe(el, "/about");
    simulateIntersect(el, true);
    (0, import_vitest.expect)(prefetched).toEqual(["/about"]);
  });
  (0, import_vitest.describe)("memory and performance", () => {
    (0, import_vitest.it)("does not leak elements after cleanup", () => {
      const elements = [];
      const cleanups = [];
      for (let i = 0; i < 100; i++) {
        const el = {};
        elements.push(el);
        cleanups.push(vp.observe(el, `/page-${i}`));
      }
      (0, import_vitest.expect)(vp.nodes.size).toBe(100);
      cleanups.forEach(c => c());
      (0, import_vitest.expect)(vp.nodes.size).toBe(0);
      (0, import_vitest.expect)(vp.done.size).toBe(0);
    });
    (0, import_vitest.it)("handles rapid observe/unobserve cycles", () => {
      const el = {};
      for (let i = 0; i < 100; i++) {
        const cleanup = vp.observe(el, "/test");
        cleanup();
      }
      (0, import_vitest.expect)(vp.nodes.size).toBe(0);
    });
  });
});