mozilla-release/testing/web-platform/tests/import-maps/core/not-as-classic-script.html

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

<script>
setup({allow_uncaught_exception : true});

const t_parse = async_test("Import maps shouldn't be parsed as scripts");
const t_evaluate = async_test("Import maps shouldn't be executed as scripts");
const t_external = async_test(
   "External import maps shouldn't be executed as scripts");

const errorHandler = event => {
  event.preventDefault();
  t_parse.unreached_func("An import map is parsed as a classic script")();
};

window.addEventListener("error", errorHandler, {once: true});
</script>

<!-- This import map causes a parse error when parsed as a classic script. -->
<script type="importmap">
{
  "imports": {
  }
}
</script>

<script>
// Remove error handler, because the following import map can causes parse
// error.
window.removeEventListener("error", errorHandler);
</script>

<script type="importmap">
t_evaluate.unreached_func("An import map is evaluated")();
</script>

<script type="importmap" src="data:text/javascript,t_external.unreached_func('An external import map is evaluated')();"></script>

<script>
t_parse.done();
t_evaluate.done();
t_external.done();
</script>