messageport-incumbent.html

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This WPT test may be referenced by the following Test IDs:
- /webmessaging/multi-globals/messageport-incumbent.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<meta charset="utf-8">

<title>Making the incumbent page become non-active must not prevent message transmission</title>

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<!-- This is the entry global -->

<iframe src="support/incumbent.html" id="incumbent"></iframe>

<iframe src="support/current.html" id="current"></iframe>

<script>

"use strict";

const incumbentIframe = document.querySelector("#incumbent");

const currentIframe = document.querySelector("#current");

window.addEventListener("load", () => {

  promise_test(async () => {

    // This will invoke the constructor from currentIframe, but with incumbentIframe as the incumbent.

    const messageChannel = incumbentIframe.contentWindow.createMessageChannel();

    await new Promise((resolve, reject) => {

      incumbentIframe.onload = () => resolve();

      incumbentIframe.onerror = () => reject(new Error("Could not navigate the iframe"));

      incumbentIframe.src = "/common/blank.html";

});

    await new Promise((resolve, reject) => {

      messageChannel.port1.onmessage = () => resolve();

      messageChannel.port1.onmessageerror = () => reject("messageerror event recieved");

      messageChannel.port2.postMessage("boo");

});

});

});

</script>