1 files changed, 41 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/moving-between-documents/ordering/parser-blocking.html b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/moving-between-documents/ordering/parser-blocking.html
new file mode 100644
index 0000000000..9edde13736
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/moving-between-documents/ordering/parser-blocking.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<link rel="help" href="https://html.spec.whatwg.org/C/#pending-parsing-blocking-script">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="helper.js"></script>
+<body>
+<script>
+const t = async_test('Script elements (parser-blocking) still block the parser in the original Document after moved to another Document');
+const start_time = performance.now();
+const iframe = document.createElement('iframe');
+document.body.appendChild(iframe);
+
+t.step_timeout(() => {
+  const script = document.querySelector('#to-be-moved');
+  iframe.contentDocument.body.appendChild(script);
+}, 1000);
+
+let syncScriptEvaluated = false;
+
+const onSyncScript = t.step_func(() => {
+  syncScriptEvaluated = true;
+
+  // The `#to-be-moved` script should block the parser and thus the sync
+  // script after `#to-be-moved` should be delayed until `#to-be-moved` is
+  // loaded (i.e. 3 seconds).
+  // Here we expect the delay should be at least 2 seconds,
+  // as the latency can be slightly less than 3 seconds due to preloading.
+  assert_greater_than(performance.now() - start_time, 2000,
+      'Parser should be blocked until script is loaded');
+});
+
+document.addEventListener('DOMContentLoaded', t.step_func_done(() => {
+  assert_true(syncScriptEvaluated,
+              'sync script should be evaluated before DOMContentLoaded');
+  assert_greater_than(performance.now() - start_time, 2000,
+      'DOMContentLoaded event should be delayed until script is loaded');
+}));
+</script>
+<script id="to-be-moved" src="../../resources/throw.js?pipe=trickle(d3)"></script>
+<script src="data:text/javascript,onSyncScript()"></script>