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

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

var import_vitest = require("vitest"), import_prefetchViewport = require("./prefetchViewport");
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, 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, !0), (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, !1), (0, import_vitest.expect)(prefetched).toEqual([]);
  }), (0, import_vitest.it)("only prefetches each href once", () => {
    const el = {};
    vp.observe(el, "/about"), simulateIntersect(el, !0), simulateIntersect(el, !1), simulateIntersect(el, !0), (0, import_vitest.expect)(prefetched).toEqual(["/about"]);
  }), (0, import_vitest.it)("cleanup re-enables prefetch for href", () => {
    const el = {}, cleanup = vp.observe(el, "/about");
    simulateIntersect(el, !0), (0, import_vitest.expect)(prefetched).toEqual(["/about"]), cleanup(), prefetched.length = 0, vp.observe(el, "/about"), simulateIntersect(el, !0), (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 = [], 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++)
        vp.observe(el, "/test")();
      (0, import_vitest.expect)(vp.nodes.size).toBe(0);
    });
  });
});
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