1 files changed, 88 insertions, 0 deletions
diff --git a/dom/base/test/chrome/bug418986-1.js b/dom/base/test/chrome/bug418986-1.js
new file mode 100644
index 0000000000..7c39df0c13
--- /dev/null
+++ b/dom/base/test/chrome/bug418986-1.js
@@ -0,0 +1,88 @@
+/* globals chromeWindow */
+// The main test function.
+var test = function (isContent) {
+  SimpleTest.waitForExplicitFinish();
+
+  SpecialPowers.pushPrefEnv({
+    set: [["security.allow_eval_with_system_principal", true]],
+  });
+
+  if (!isContent) {
+    let { ww } = SpecialPowers.Services;
+    window.chromeWindow = ww.activeWindow;
+  }
+
+  // The pairs of values expected to be the same when
+  // fingerprinting resistance is enabled.
+  let pairs = [
+    ["screenX", 0],
+    ["screenY", 0],
+    ["mozInnerScreenX", 0],
+    ["mozInnerScreenY", 0],
+    ["screen.pixelDepth", 24],
+    ["screen.colorDepth", 24],
+    ["screen.availWidth", "innerWidth"],
+    ["screen.availHeight", "innerHeight"],
+    ["screen.left", 0],
+    ["screen.top", 0],
+    ["screen.availLeft", 0],
+    ["screen.availTop", 0],
+    ["screen.width", "innerWidth"],
+    ["screen.height", "innerHeight"],
+    ["screen.orientation.type", "'landscape-primary'"],
+    ["screen.orientation.angle", 0],
+    ["screen.mozOrientation", "'landscape-primary'"],
+    ["devicePixelRatio", 1],
+  ];
+
+  // checkPair: tests if members of pair [a, b] are equal when evaluated.
+  let checkPair = function (a, b) {
+    // eslint-disable-next-line no-eval
+    is(eval(a), eval(b), a + " should be equal to " + b);
+  };
+
+  // Returns generator object that iterates through pref values.
+  let prefVals = (function* () {
+    yield false;
+    yield true;
+  })();
+
+  // The main test function, runs until all pref values are exhausted.
+  let nextTest = function () {
+    let { value: prefValue, done } = prefVals.next();
+    if (done) {
+      SimpleTest.finish();
+      return;
+    }
+    SpecialPowers.pushPrefEnv(
+      { set: [["privacy.resistFingerprinting", prefValue]] },
+      function () {
+        // We will be resisting fingerprinting if the pref is enabled,
+        // and we are in a content script (not chrome).
+        let resisting = prefValue && isContent;
+        // Check each of the pairs.
+        pairs.map(function ([item, onVal]) {
+          if (resisting) {
+            checkPair("window." + item, onVal);
+          } else if (!isContent && !item.startsWith("moz")) {
+            checkPair("window." + item, "chromeWindow." + item);
+          }
+        });
+        if (!isContent && !resisting) {
+          // Hard to predict these values, but we can enforce constraints:
+          ok(
+            window.mozInnerScreenX >= chromeWindow.mozInnerScreenX,
+            "mozInnerScreenX"
+          );
+          ok(
+            window.mozInnerScreenY >= chromeWindow.mozInnerScreenY,
+            "mozInnerScreenY"
+          );
+        }
+        nextTest();
+      }
+    );
+  };
+
+  nextTest();
+};