text: def main(request, response):
      headers = [(b"Content-Type", b"application/javascript")]
  
      body = {u'parse-error': u'var foo = function() {;',
              u'undefined-error': u'foo.bar = 42;',
              u'uncaught-exception': u'throw new DOMException("AbortError");',
              u'caught-exception': u'try { throw new Error; } catch(e) {}',
              u'import-malformed-script': u'importScripts("malformed-worker.py?parse-error");',
              u'import-no-such-script': u'importScripts("no-such-script.js");'}[request.url_parts.query]
      return headers, body
  