chromium/third_party/blink/web_tests/wpt_internal/reporting/intervention.html

<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/intervention.js"></script>

<div id="target" style="padding: 10px; background-color: blue;">
  <p>Testing intervention reports and ReportingObserver</p>
</div>

<script>
async_test(function(test) {
  var kInterventionReport = 2531; // From web_feature.mojom.

  var observer = new ReportingObserver(function(reports, observer) {
    test.step(function() {
      assert_equals(reports.length, 1);
      assert_true(internals.isUseCounted(document, kInterventionReport));

      // Ensure that the contents of the report are valid.
      assert_equals(reports[0].type, "intervention");
      assert_true(reports[0].url.endsWith("reporting/intervention.html"));
      assert_equals(typeof reports[0].body.id, "string");
      assert_true(reports[0].body.sourceFile.endsWith(
          "reporting/resources/intervention.js"));
      assert_equals(typeof reports[0].body.lineNumber, "number");
      assert_equals(typeof reports[0].body.columnNumber, "number");
      assert_equals(typeof reports[0].body.message, "string");

      // Ensure the toJSON call is successful.
      const reportJSON = reports[0].toJSON();
      assert_equals(reportJSON.type, reports[0].type);
      assert_equals(reportJSON.url, reports[0].url);
      assert_equals(typeof reportJSON.body, "object");
      assert_equals(reportJSON.body.id, reports[0].body.id);
      assert_equals(reportJSON.body.message, reports[0].body.message);
      assert_equals(reportJSON.body.sourceFile, reports[0].body.sourceFile);
      assert_equals(reportJSON.body.lineNumber, reports[0].body.lineNumber);
      assert_equals(reportJSON.body.columnNumber, reports[0].body.columnNumber);
      // Ensure that report can be successfully JSON serialized.
      assert_false(JSON.stringify(reports[0]) === "{}");
      assert_equals(JSON.stringify(reports[0]), JSON.stringify(reportJSON));
    });

    test.done();
  });
  observer.observe();

  assert_false(internals.isUseCounted(document, kInterventionReport));
  causeIntervention();
}, "Intervention report");
</script>