1 files changed, 40 insertions, 0 deletions
diff --git a/toolkit/components/extensions/test/xpcshell/test_resistfingerprinting_exempt.js b/toolkit/components/extensions/test/xpcshell/test_resistfingerprinting_exempt.js
new file mode 100644
index 0000000000..ff4c9bd74b
--- /dev/null
+++ b/toolkit/components/extensions/test/xpcshell/test_resistfingerprinting_exempt.js
@@ -0,0 +1,40 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set sts=2 sw=2 et tw=80: */
+"use strict";
+
+async function queryBuildID() {
+  let extension = ExtensionTestUtils.loadExtension({
+    background() {
+      browser.test.sendMessage("result", { buildID: navigator.buildID });
+    },
+  });
+  await extension.startup();
+  let { buildID } = await extension.awaitMessage("result");
+  await extension.unload();
+  return buildID;
+}
+
+const BUILDID_OVERRIDE = "Overridden buildID";
+
+add_task(
+  {
+    pref_set: [["general.buildID.override", BUILDID_OVERRIDE]],
+  },
+  async function test_buildID_normal() {
+    let buildID = await queryBuildID();
+    Assert.equal(buildID, BUILDID_OVERRIDE);
+  }
+);
+
+add_task(
+  {
+    pref_set: [
+      ["general.buildID.override", BUILDID_OVERRIDE],
+      ["privacy.resistFingerprinting", true],
+    ],
+  },
+  async function test_buildID_resistFingerprinting() {
+    let buildID = await queryBuildID();
+    Assert.equal(buildID, BUILDID_OVERRIDE);
+  }
+);