gecko-dev/testing/web-platform/tests/mixed-content/generic/template/test.js.template

MixedContentTestCase(
  {
    "opt_in_method": "%(opt_in_method)s",
    "origin": "%(origin)s",
    "source_scheme": "%(source_scheme)s",
    "context_nesting": "%(context_nesting)s",
    "redirection": "%(redirection)s",
    "subresource": "%(subresource)s",
    "expectation": "%(expectation)s"
  },
  document.querySelector("meta[name=assert]").content,
  new SanityChecker()
).start();