Script: Add execution timing test for no-import module script

domfarolino · chromium-wpt-export-bot · commit 343bf53492d8 · 2023-03-25T12:27:02.000-07:00
Both Chrome and Safari agree that module scripts with no imports run asynchronously, per the semi-ambiguous language in the HTML Standard discussed in whatwg/html#3746, despite the script being "ready" immediately. Firefox seems to implement the spec correctly, regarding the "readiness" being synchronous, however with 2/3 implementations *not* implementing the spec in this regard, and an open spec issue in this area, I find it unlikely that Chromium's will change its behavior (for compat). I'll recommend on the spec issue that we change the spec to match Safari and Chrome, and land this test asserting the majority behavior. R=domenic@chromium.org Bug: N/A Change-Id: Ibeac277ab357b62e7d0a5e4afb5f95818a2d4005
diff --git a/html/semantics/scripting-1/the-script-element/execution-timing/non-external-no-import.html b/html/semantics/scripting-1/the-script-element/execution-timing/non-external-no-import.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>Module scripts with no imports always execute asynchronously</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <link rel="help" href="https://github.com/whatwg/html/issues/3746">
+</head>
+<body>
+<script>
+async_test(t => {
+  window.results = [];
+  window.logExecution = msg => window.results.push(msg);
+
+  const script = document.createElement('script');
+  script.type = 'module';
+  script.textContent = "window.logExecution('module')";
+  document.body.append(script);
+  window.logExecution('classic');
+
+  window.onload = t.step_func_done(e => {
+    assert_array_equals(window.results, ['classic', 'module']);
+  });
+}, document.title);
+</script>
+</body>
+</html>
