test_ext_canvas_resistFingerprinting.html

Enable keyboard shortcuts

<!DOCTYPE HTML>

<html>

<head>

  <title>WebExtension test</title>

  <script src="/tests/SimpleTest/SimpleTest.js"></script>

  <script src="/tests/SimpleTest/ExtensionTestUtils.js"></script>

  <script type="text/javascript" src="head.js"></script>

  <script type="text/javascript" src="head_cookies.js"></script>

  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>

</head>

<body>

<script type="text/javascript">

"use strict";

add_task(async function setup() {

  await SpecialPowers.pushPrefEnv({

    set: [["privacy.resistFingerprinting", true]],

});

});

add_task(async function test_contentscript() {

  function contentScript() {

    let canvas = document.createElement("canvas");

    canvas.width = canvas.height = "100";

    let ctx = canvas.getContext("2d");

    ctx.fillStyle = "green";

    ctx.fillRect(0, 0, 100, 100);

    let data = ctx.getImageData(50, 50, 1, 1);

    browser.test.sendMessage("data-color", data.data[1]);

  let extensionData = {

    manifest: {

      content_scripts: [

          "matches": ["http://mochi.test/*/file_sample.html"],

          "js": ["content_script.js"],

          "run_at": "document_start",

},

],

},

    files: {

      "content_script.js": contentScript,

},

};

  const url = "http://mochi.test:8888/chrome/toolkit/components/extensions/test/mochitest/file_sample.html";

  let extension = ExtensionTestUtils.loadExtension(extensionData);

  await extension.startup();

  let win = window.open(url);

  let color = await extension.awaitMessage("data-color");

  const expected = 128;

  is(color, expected, "Got correct pixel data for green");

  win.close();

  await extension.unload();

});

</script>

</body>

</html>