servo/tests/wpt/web-platform-tests/upgrade-insecure-requests/generic/test-case.sub.js

// TODO(hiroshige): Document the type of `scenario`.
function TestCase(scenarios) {
  function runTest(scenario) {
    const urls = getRequestURLs(scenario.subresource,
                                scenario.origin,
                                scenario.redirection);
    const checkResult = _ => {
      // Send request to check if the key has been torn down.
      return xhrRequest(urls.assertUrl)
        .then(assertResult => {
            // Now check if the value has been torn down. If it's still there,
            // we have blocked the request to mixed-content.
            assert_equals(assertResult.status, scenario.expectation,
              "The resource request should be '" + scenario.expectation + "'.");
          });
    };

    /** @type {Subresource} */
    const subresource = {
      subresourceType: scenario.subresource,
      url: urls.testUrl,
      policyDeliveries: scenario.subresource_policy_deliveries,
    };

    promise_test(() => {
      return xhrRequest(urls.announceUrl)
        // Send out the real resource request.
        // This should tear down the key if it's not blocked.
        .then(_ => invokeRequest(subresource, scenario.source_context_list))
        // We check the key state, regardless of whether the main request
        // succeeded or failed.
        .then(checkResult, checkResult);
      }, scenario.test_description);
  }  // runTest

  function runTests() {
    for (const scenario of scenarios) {
      runTest(scenario);
    }
  }

  return {start: runTests};
}