chromium/third_party/blink/web_tests/external/wpt/eventsource/dedicated-worker/eventsource-onmesage.js

try {
  var source = new EventSource("../resources/message.py")
  source.onmessage = function(e) {
    postMessage([true, e.data])
    this.close()
  }
} catch(e) {
  postMessage([false, String(e)])
}