performance-speculations-unused-preload.tentative.html

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This test has a WPT meta file that expects 10 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /speculation-rules/speculation-measurement/performance-speculations-unused-preload.tentative.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<meta charset="utf-8">

<title>performance.getSpeculations() - unused preloads with various as/crossorigin</title>

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<script src="support/speculation-measurement-utils.js"></script>

<body>

<script>

// Verify basic interface shape before any preloads are added.

test(() => {

  assert_true(isSpeculationMeasurementEnabled(),

    "SpeculationMeasurement feature must be enabled");

  assert_true('SpeculationData' in window, "SpeculationData should exist");

  assert_true('PreloadData' in window, "PreloadData should exist");

  const speculations = performance.getSpeculations();

  assert_not_equals(speculations, null);

  assert_not_equals(speculations, undefined);

  assert_true('preloads' in speculations, "should have preloads");

  assert_true(Array.isArray(speculations.preloads), "preloads should be array");

  assert_array_equals(speculations.preloads, [],

    "preloads should be empty when page has no preloads");

}, "performance.getSpeculations() basic interface");

// Test matrix: combinations of "as" and "crossorigin" for unused preloads.

const testCases = [

  {as: 'script', crossorigin: null},

  {as: 'script', crossorigin: 'anonymous'},

  {as: 'script', crossorigin: 'use-credentials'},

  {as: 'style',  crossorigin: null},

  {as: 'style',  crossorigin: 'anonymous'},

  {as: 'style',  crossorigin: 'use-credentials'},

  {as: 'fetch',  crossorigin: null},

  {as: 'fetch',  crossorigin: 'anonymous'},

  {as: 'fetch',  crossorigin: 'use-credentials'},

];

for (const {as, crossorigin} of testCases) {

  const coLabel = crossorigin === null ? 'no crossorigin' :

                                         `crossorigin=${crossorigin}`;

  promise_test(async t => {

    const tag = `${as}-${crossorigin}-unused`;

    const href = supportFileUrl(as, tag);

    await addPreloadAndWait({t, as, crossorigin, href});

    const preload = findPreloadByUrl(performance.getSpeculations().preloads, tag);

    assert_not_equals(preload, undefined, "preload entry should exist");

    assert_equals(preload.as, as, `as should be '${as}'`);

    assert_equals(preload.crossorigin, expectedCrossOriginMode(crossorigin),

      `crossorigin should be '${expectedCrossOriginMode(crossorigin)}'`);

    assert_equals(preload.used, null, "unused preload should have used=null");

  }, `Unused preload: as=${as}, ${coLabel}`);

</script>

</body>