1 files changed, 318 insertions, 0 deletions
diff --git a/layout/style/test/chrome/bug418986-2.js b/layout/style/test/chrome/bug418986-2.js
new file mode 100644
index 0000000000..6d2af235c3
--- /dev/null
+++ b/layout/style/test/chrome/bug418986-2.js
@@ -0,0 +1,318 @@
+// # Bug 418986, part 2.
+
+const is_chrome_window = window.location.protocol === "chrome:";
+
+const HTML_NS = "http://www.w3.org/1999/xhtml";
+
+// Expected values. Format: [name, pref_off_value, pref_on_value]
+// If pref_*_value is an array with two values, then we will match
+// any value in between those two values. If a value is null, then
+// we skip the media query.
+var expected_values = [
+  ["color", null, 8],
+  ["color-index", null, 0],
+  ["aspect-ratio", null, window.innerWidth + "/" + window.innerHeight],
+  [
+    "device-aspect-ratio",
+    screen.width + "/" + screen.height,
+    window.innerWidth + "/" + window.innerHeight,
+  ],
+  ["device-height", screen.height + "px", window.innerHeight + "px"],
+  ["device-width", screen.width + "px", window.innerWidth + "px"],
+  ["grid", null, 0],
+  ["height", window.innerHeight + "px", window.innerHeight + "px"],
+  ["monochrome", null, 0],
+  // Square is defined as portrait:
+  [
+    "orientation",
+    null,
+    window.innerWidth > window.innerHeight ? "landscape" : "portrait",
+  ],
+  ["resolution", null, "96dpi"],
+  [
+    "resolution",
+    [
+      0.999 * window.devicePixelRatio + "dppx",
+      1.001 * window.devicePixelRatio + "dppx",
+    ],
+    "1dppx",
+  ],
+  ["width", window.innerWidth + "px", window.innerWidth + "px"],
+  ["-moz-device-pixel-ratio", window.devicePixelRatio, 1],
+  [
+    "-moz-device-orientation",
+    screen.width > screen.height ? "landscape" : "portrait",
+    window.innerWidth > window.innerHeight ? "landscape" : "portrait",
+  ],
+];
+
+// These media queries return value 0 or 1 when the pref is off.
+// When the pref is on, they should not match.
+var suppressed_toggles = [
+  // Not available on most OSs.
+  "-moz-scrollbar-end-backward",
+  "-moz-scrollbar-end-forward",
+  "-moz-scrollbar-start-backward",
+  "-moz-scrollbar-start-forward",
+  "-moz-gtk-csd-available",
+  "-moz-gtk-csd-minimize-button",
+  "-moz-gtk-csd-maximize-button",
+  "-moz-gtk-csd-close-button",
+  "-moz-gtk-csd-reversed-placement",
+];
+
+var toggles_enabled_in_content = [];
+
+// Read the current OS.
+var OS = SpecialPowers.Services.appinfo.OS;
+
+// __keyValMatches(key, val)__.
+// Runs a media query and returns true if key matches to val.
+var keyValMatches = (key, val) =>
+  matchMedia("(" + key + ":" + val + ")").matches;
+
+// __testMatch(key, val)__.
+// Attempts to run a media query match for the given key and value.
+// If value is an array of two elements [min max], then matches any
+// value in-between.
+var testMatch = function (key, val) {
+  if (val === null) {
+    return;
+  } else if (Array.isArray(val)) {
+    ok(
+      keyValMatches("min-" + key, val[0]) &&
+        keyValMatches("max-" + key, val[1]),
+      "Expected " + key + " between " + val[0] + " and " + val[1]
+    );
+  } else {
+    ok(keyValMatches(key, val), "Expected " + key + ":" + val);
+  }
+};
+
+// __testToggles(resisting)__.
+// Test whether we are able to match the "toggle" media queries.
+var testToggles = function (resisting) {
+  suppressed_toggles.forEach(function (key) {
+    var exists = keyValMatches(key, 0) || keyValMatches(key, 1);
+    if (!toggles_enabled_in_content.includes(key) && !is_chrome_window) {
+      ok(!exists, key + " should not exist.");
+    } else {
+      ok(exists, key + " should exist.");
+      if (resisting) {
+        ok(
+          keyValMatches(key, 0) && !keyValMatches(key, 1),
+          "Should always match as false"
+        );
+      }
+    }
+  });
+};
+
+// __generateHtmlLines(resisting)__.
+// Create a series of div elements that look like:
+// `<div class='spoof' id='resolution'>resolution</div>`,
+// where each line corresponds to a different media query.
+var generateHtmlLines = function (resisting) {
+  let fragment = document.createDocumentFragment();
+  expected_values.forEach(function ([key, offVal, onVal]) {
+    let val = resisting ? onVal : offVal;
+    if (val) {
+      let div = document.createElementNS(HTML_NS, "div");
+      div.setAttribute("class", "spoof");
+      div.setAttribute("id", key);
+      div.textContent = key;
+      fragment.appendChild(div);
+    }
+  });
+  suppressed_toggles.forEach(function (key) {
+    let div = document.createElementNS(HTML_NS, "div");
+    div.setAttribute("class", "suppress");
+    div.setAttribute("id", key);
+    div.textContent = key;
+    fragment.appendChild(div);
+  });
+  return fragment;
+};
+
+// __cssLine__.
+// Creates a line of css that looks something like
+// `@media (resolution: 1ppx) { .spoof#resolution { background-color: green; } }`.
+var cssLine = function (query, clazz, id, color) {
+  return (
+    "@media " +
+    query +
+    " { ." +
+    clazz +
+    "#" +
+    id +
+    " { background-color: " +
+    color +
+    "; } }\n"
+  );
+};
+
+// __constructQuery(key, val)__.
+// Creates a CSS media query from key and val. If key is an array of
+// two elements, constructs a range query (using min- and max-).
+var constructQuery = function (key, val) {
+  return Array.isArray(val)
+    ? "(min-" + key + ": " + val[0] + ") and (max-" + key + ": " + val[1] + ")"
+    : "(" + key + ": " + val + ")";
+};
+
+// __mediaQueryCSSLine(key, val, color)__.
+// Creates a line containing a CSS media query and a CSS expression.
+var mediaQueryCSSLine = function (key, val, color) {
+  if (val === null) {
+    return "";
+  }
+  return cssLine(constructQuery(key, val), "spoof", key, color);
+};
+
+// __suppressedMediaQueryCSSLine(key, color)__.
+// Creates a CSS line that matches the existence of a
+// media query that is supposed to be suppressed.
+var suppressedMediaQueryCSSLine = function (key, color, suppressed) {
+  let query = "(" + key + ": 0), (" + key + ": 1)";
+  return cssLine(query, "suppress", key, color);
+};
+
+// __generateCSSLines(resisting)__.
+// Creates a series of lines of CSS, each of which corresponds to
+// a different media query. If the query produces a match to the
+// expected value, then the element will be colored green.
+var generateCSSLines = function (resisting) {
+  let lines = ".spoof { background-color: red;}\n";
+  expected_values.forEach(function ([key, offVal, onVal]) {
+    lines += mediaQueryCSSLine(key, resisting ? onVal : offVal, "green");
+  });
+  lines +=
+    ".suppress { background-color: " + (resisting ? "green" : "red") + ";}\n";
+  suppressed_toggles.forEach(function (key) {
+    if (
+      !toggles_enabled_in_content.includes(key) &&
+      !resisting &&
+      !is_chrome_window
+    ) {
+      lines += "#" + key + " { background-color: green; }\n";
+    } else {
+      lines += suppressedMediaQueryCSSLine(key, "green");
+    }
+  });
+  return lines;
+};
+
+// __green__.
+// Returns the computed color style corresponding to green.
+var green = "rgb(0, 128, 0)";
+
+// __testCSS(resisting)__.
+// Creates a series of divs and CSS using media queries to set their
+// background color. If all media queries match as expected, then
+// all divs should have a green background color.
+var testCSS = function (resisting) {
+  document.getElementById("display").appendChild(generateHtmlLines(resisting));
+  document.getElementById("test-css").textContent = generateCSSLines(resisting);
+  let cssTestDivs = document.querySelectorAll(".spoof,.suppress");
+  for (let div of cssTestDivs) {
+    let color = window.getComputedStyle(div).backgroundColor;
+    ok(color === green, "CSS for '" + div.id + "'");
+  }
+};
+
+// __testOSXFontSmoothing(resisting)__.
+// When fingerprinting resistance is enabled, the `getComputedStyle`
+// should always return `undefined` for `MozOSXFontSmoothing`.
+var testOSXFontSmoothing = function (resisting) {
+  let div = document.createElementNS(HTML_NS, "div");
+  div.style.MozOsxFontSmoothing = "unset";
+  document.documentElement.appendChild(div);
+  let readBack = window.getComputedStyle(div).MozOsxFontSmoothing;
+  div.remove();
+  let smoothingPref = SpecialPowers.getBoolPref(
+    "layout.css.osx-font-smoothing.enabled",
+    false
+  );
+  is(
+    readBack,
+    resisting ? "" : smoothingPref ? "auto" : "",
+    "-moz-osx-font-smoothing"
+  );
+};
+
+// __sleep(timeoutMs)__.
+// Returns a promise that resolves after the given timeout.
+var sleep = function (timeoutMs) {
+  return new Promise(function (resolve, reject) {
+    window.setTimeout(resolve);
+  });
+};
+
+// __testMediaQueriesInPictureElements(resisting)__.
+// Test to see if media queries are properly spoofed in picture elements
+// when we are resisting fingerprinting.
+var testMediaQueriesInPictureElements = async function (resisting) {
+  const MATCH = "/tests/layout/style/test/chrome/match.png";
+  let container = document.getElementById("pictures");
+  let testImages = [];
+  for (let [key, offVal, onVal] of expected_values) {
+    let expected = resisting ? onVal : offVal;
+    if (expected) {
+      let picture = document.createElementNS(HTML_NS, "picture");
+      let query = constructQuery(key, expected);
+      ok(matchMedia(query).matches, `${query} should match`);
+
+      let source = document.createElementNS(HTML_NS, "source");
+      source.setAttribute("srcset", MATCH);
+      source.setAttribute("media", query);
+
+      let image = document.createElementNS(HTML_NS, "img");
+      image.setAttribute("title", key + ":" + expected);
+      image.setAttribute("class", "testImage");
+      image.setAttribute("src", "/tests/layout/style/test/chrome/mismatch.png");
+      image.setAttribute("alt", key);
+
+      testImages.push(image);
+
+      picture.appendChild(source);
+      picture.appendChild(image);
+      container.appendChild(picture);
+    }
+  }
+  const matchURI = new URL(MATCH, document.baseURI).href;
+  await sleep(0);
+  for (let testImage of testImages) {
+    is(
+      testImage.currentSrc,
+      matchURI,
+      "Media query '" + testImage.title + "' in picture should match."
+    );
+  }
+};
+
+// __pushPref(key, value)__.
+// Set a pref value asynchronously, returning a promise that resolves
+// when it succeeds.
+var pushPref = function (key, value) {
+  return new Promise(function (resolve, reject) {
+    SpecialPowers.pushPrefEnv({ set: [[key, value]] }, resolve);
+  });
+};
+
+// __test(isContent)__.
+// Run all tests.
+var test = async function (isContent) {
+  for (prefValue of [false, true]) {
+    await pushPref("privacy.resistFingerprinting", prefValue);
+    let resisting = prefValue && isContent;
+    expected_values.forEach(function ([key, offVal, onVal]) {
+      testMatch(key, resisting ? onVal : offVal);
+    });
+    testToggles(resisting);
+    testCSS(resisting);
+    if (OS === "Darwin") {
+      testOSXFontSmoothing(resisting);
+    }
+    await testMediaQueriesInPictureElements(resisting);
+  }
+};