browser_webconsole_lenient_this_warning.js

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/* Any copyright is dedicated to the Public Domain.

 * http://creativecommons.org/publicdomain/zero/1.0/ */

"use strict";

// Check that calling the LenientThis warning is only called when expected.

const TEST_URI = `data:text/html;charset=utf8,<!DOCTYPE html>${encodeURI(`

    <h1>LenientThis warning</h1>

    <script>

      const el = document.createElement('div');

      globalThis.htmlDivElementProto = Object.getPrototypeOf(el);

      function triggerLenientThisWarning(){

        Object.getOwnPropertyDescriptor(

          Object.getPrototypeOf(globalThis.htmlDivElementProto),

          'onmouseenter'

        ).get.call()

    </script>`)}`;

add_task(async function () {

  const hud = await openNewTabAndConsole(TEST_URI);

  const expectedWarningMessageText =

    "Ignoring get or set of property that has [LenientThis] ";

  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {

    const global = content.wrappedJSObject;

    global.console.log(global.htmlDivElementProto);

});

  info("Wait for a bit so any warning message could be displayed");

  await wait(1000);

  await waitFor(() => findConsoleAPIMessage(hud, "HTMLDivElementPrototype"));

ok(

    !findWarningMessage(hud, expectedWarningMessageText, ".warn"),

    "Displaying the HTMLDivElementPrototype does not trigger the LenientThis warning"

);

  info(

    "Call a LenientThis getter with the wrong `this` to trigger a warning message"

);

  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {

    content.wrappedJSObject.triggerLenientThisWarning();

});

  await waitFor(() =>

    findWarningMessage(hud, expectedWarningMessageText, ".warn")

);

ok(

    true,

    "Calling the LenientThis getter with an unexpected `this` did triggered the warning"

);

  info(

    "Clear the console and call the LenientThis getter with an unexpected `this` again"

);

  await clearOutput(hud);

  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {

    content.wrappedJSObject.triggerLenientThisWarning();

});

  info("Wait for a bit so any warning message could be displayed");

  await wait(1000);

ok(

    !findWarningMessage(hud, expectedWarningMessageText, ".warn"),

    "Calling the LenientThis getter a second time did not trigger the warning again"

);

});