1 files changed, 126 insertions, 0 deletions
diff --git a/dom/security/test/referrer-policy/browser_referrer_telemetry.js b/dom/security/test/referrer-policy/browser_referrer_telemetry.js
new file mode 100644
index 0000000000..7542dd9338
--- /dev/null
+++ b/dom/security/test/referrer-policy/browser_referrer_telemetry.js
@@ -0,0 +1,126 @@
+/**
+ * Bug 1720869 - Testing the referrer policy telemetry.
+ */
+
+"use strict";
+
+const TEST_DOMAIN = "https://example.com/";
+const TEST_CROSS_SITE_DOMAIN = "https://test1.example.org/";
+
+const TEST_PATH = "browser/dom/security/test/referrer-policy/";
+
+const TEST_PAGE = `${TEST_DOMAIN}${TEST_PATH}referrer_page.sjs`;
+const TEST_CROSS_SITE_PAGE = `${TEST_CROSS_SITE_DOMAIN}${TEST_PATH}referrer_page.sjs`;
+
+// This matches to the order in ReferrerPolicy.webidl
+const REFERRER_POLICY_INDEX = {
+  empty: 0,
+  "no-referrer": 1,
+  "no-referrer-when-downgrade": 2,
+  origin: 3,
+  "origin-when-cross-origin": 4,
+  "unsafe-url": 5,
+  "same-origin": 6,
+  "strict-origin": 7,
+  "strict-origin-when-cross-origin": 8,
+};
+
+const TEST_CASES = [
+  {
+    policy: "",
+    expected: REFERRER_POLICY_INDEX.empty,
+  },
+  {
+    policy: "no-referrer",
+    expected: REFERRER_POLICY_INDEX["no-referrer"],
+  },
+  {
+    policy: "no-referrer-when-downgrade",
+    expected: REFERRER_POLICY_INDEX["no-referrer-when-downgrade"],
+  },
+  {
+    policy: "origin",
+    expected: REFERRER_POLICY_INDEX.origin,
+  },
+  {
+    policy: "origin-when-cross-origin",
+    expected: REFERRER_POLICY_INDEX["origin-when-cross-origin"],
+  },
+  {
+    policy: "same-origin",
+    expected: REFERRER_POLICY_INDEX["same-origin"],
+  },
+  {
+    policy: "strict-origin",
+    expected: REFERRER_POLICY_INDEX["strict-origin"],
+  },
+  {
+    policy: "strict-origin-when-cross-origin",
+    expected: REFERRER_POLICY_INDEX["strict-origin-when-cross-origin"],
+  },
+  {
+    policy: "unsafe-url",
+    expected: REFERRER_POLICY_INDEX["unsafe-url"],
+  },
+];
+
+function clearTelemetry() {
+  Services.telemetry.getSnapshotForHistograms("main", true /* clear */);
+  Services.telemetry.getHistogramById("REFERRER_POLICY_COUNT").clear();
+}
+
+add_setup(async function () {
+  // Clear Telemetry probes before testing.
+  clearTelemetry();
+});
+
+function verifyTelemetry(expected, isSameSite) {
+  // The record of cross-site loads is placed in the second half of the
+  // telemetry.
+  const offset = isSameSite ? 0 : Object.keys(REFERRER_POLICY_INDEX).length;
+
+  let histograms = Services.telemetry.getSnapshotForHistograms(
+    "main",
+    false /* clear */
+  ).parent;
+
+  let referrerPolicyCountProbe = histograms.REFERRER_POLICY_COUNT;
+
+  ok(referrerPolicyCountProbe, "The telemetry probe has been recorded.");
+  is(
+    referrerPolicyCountProbe.values[expected + offset],
+    1,
+    "The telemetry is added correctly."
+  );
+}
+
+add_task(async function run_tests() {
+  for (let test of TEST_CASES) {
+    for (let sameSite of [true, false]) {
+      clearTelemetry();
+      let referrerURL = `${TEST_PAGE}?header=${test.policy}`;
+
+      await BrowserTestUtils.withNewTab(referrerURL, async browser => {
+        let iframeURL = sameSite
+          ? TEST_PAGE + "?show"
+          : TEST_CROSS_SITE_PAGE + "?show";
+
+        // Create an iframe and load the url.
+        await SpecialPowers.spawn(browser, [iframeURL], async url => {
+          let iframe = content.document.createElement("iframe");
+          iframe.src = url;
+
+          await new content.Promise(resolve => {
+            iframe.onload = () => {
+              resolve();
+            };
+
+            content.document.body.appendChild(iframe);
+          });
+        });
+
+        verifyTelemetry(test.expected, sameSite);
+      });
+    }
+  }
+});