firefox/testing/web-platform/tests/workers/data-url.html

<!DOCTYPE html>
<title>data URL dedicated workers</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
// Helper assert functions -START-
function assert_worker_sends_pass(test_desc, mime_type, worker_code) {
  async_test(function(t) {
    var w = new Worker(`data:${mime_type},${worker_code}`);
    w.onmessage = t.step_func_done(function(e) {
      assert_equals(e.data, 'PASS');
    });
    w.postMessage('SEND_PASS');
  }, test_desc);
}

function assert_worker_throws(test_desc, worker_code) {
  assert_worker_sends_pass(test_desc, '', `try { ${worker_code}; self.postMessage("FAIL"); } catch (e) { self.postMessage("PASS"); }`);
}

function assert_worker_construction_fails(test_desc, mime_type, worker_code) {
  async_test(function(t) {
    var w = new Worker(`data:${mime_type},${worker_code};postMessage("PASS")`);
    w.onmessage = t.step_func_done(function(e) {
      assert_unreached('Should not receive any message back.');
    });
    w.onerror = t.step_func_done(function(e) {
      assert_true(true, 'Should throw ' + e.message);
      // Stop the error from being propagated to the WPT test harness
      e.preventDefault();
    });
  }, test_desc);
}
// Helper assert functions -END-

// Actual tests -START-

// Any MIME type allowed
assert_worker_sends_pass('application/javascript MIME allowed', 'application/javascript', 'self.postMessage("PASS")');
assert_worker_sends_pass('text/plain MIME allowed', 'text/plain', 'self.postMessage("PASS")');
assert_worker_sends_pass('empty MIME allowed', '', 'self.postMessage("PASS")');

// Communications goes both ways
assert_worker_sends_pass('communication goes both ways', 'application/javascript', 'onmessage = function(e) { self.postMessage("PASS"); }');

// test access to storage APIs

// https://w3c.github.io/IndexedDB/#dom-idbfactory-open
assert_worker_sends_pass('indexedDB is present', '', 'self.postMessage("indexedDB" in self ? "PASS" : "FAIL")');
assert_worker_throws('indexedDB is inaccessible', 'self.indexedDB.open("someDBName")');

// Other standardized storage APIs are either not exposed to workers
// (e.g. window.localStorage, window.sessionStorage), or are [SecureContext]
// (e.g. self.caches).

// 'data:' workers are cross-origin
assert_worker_sends_pass('cross-origin worker', '', 'fetch("/").then(() => self.postMessage("FAIL"), () => self.postMessage("PASS"))');

// 'data:' workers have opaque origin
assert_worker_sends_pass('worker has opaque origin', 'application/javascript', 'if (self.location.origin == "null") {postMessage("PASS");} else {postMessage("FAIL");}');

setup({allow_uncaught_exception:true});
// invalid javascript will trigger an ErrorEvent
assert_worker_construction_fails('invalid javascript produces error', 'application/javascript', '}x=3');

// Actual tests -END-
</script>