test_bug_2058272.html

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<meta charset=utf-8>

<title>Test dynamic import from a module shared by two preloaded graphs</title>

<script src="/tests/SimpleTest/SimpleTest.js"></script>

<body>

<script>

  SimpleTest.waitForExplicitFinish();

  // A trivial module used as the dynamic import target.

  const INNER = "data:text/javascript,export default 1";

  // The leaf of the first preloaded graph. It performs a dynamic import when it

  // runs.

  const LEAF_BODY =

    'import("' + INNER + '").then(' +

    '() => { window.postMessage("shared-ok", "*"); }, ' +

    '(e) => { window.postMessage("shared-fail:" + e, "*"); });' +

    'export default 3;';

  const LEAF = "data:text/javascript," + encodeURIComponent(LEAF_BODY);

  // The node shared by both graphs. It statically imports LEAF.

  const SHARED_BODY = 'import "' + LEAF + '"; export default 2;';

  const SHARED = "data:text/javascript," + encodeURIComponent(SHARED_BODY);

  // The __second assignment makes FIRST and SECOND non-identifical.

  const FIRST_BODY = 'import "' + SHARED + '";';

  const FIRST = "data:text/javascript," + encodeURIComponent(FIRST_BODY);

  const SECOND_BODY = 'import "' + SHARED + '"; window.__second = 1;';

  const SECOND = "data:text/javascript," + encodeURIComponent(SECOND_BODY);

  window.addEventListener("message", (e) => {

    is(e.data, "shared-ok",

       "Dynamic import from a module shared by two preload graphs should succeed.");

    ok(window.__second == 1, "The promoted top-level module should have run.");

    SimpleTest.finish();

});

  // Preload FIRST (FIRST -> SHARED -> LEAF) to completion. LEAF's specifier

  // resolution record is recorded against FIRST's preloaded resolved set.

//

  // Then preload SECOND (SECOND -> SHARED). SHARED is already fetched, so its

  // subtree is not re-walked and LEAF's record never lands in SECOND's set.

//

  // Then injects the <script type="module" src="SECOND>.

  // The SECOND module graph doesn't contain the LEAF node.

  const linkFirst = document.createElement("link");

  linkFirst.rel = "modulepreload";

  linkFirst.href = FIRST;

  linkFirst.addEventListener("load", () => {

    const linkSecond = document.createElement("link");

    linkSecond.rel = "modulepreload";

    linkSecond.href = SECOND;

    linkSecond.addEventListener("load", () => {

      const s = document.createElement("script");

      s.type = "module";

      s.src = SECOND;

      document.body.appendChild(s);

});

    document.head.appendChild(linkSecond);

});

  document.head.appendChild(linkFirst);

</script>

</body>